IMO E
evidence of is incorrect in this context.
evidence of is correct in C but basing them is awkward.
so evidence that.
eliminate B,D,C.
E is in simple past.

beat_gmat_09 wrote:IMO E
evidence of is incorrect in this context.
evidence of is correct in C but basing them is awkward.
so evidence that.
eliminate B,D,C.
E is in simple past.

More specifically, the present perfect (denoting ongoing or recently-completed actions) in A is ridiculous -- a centuries-old stick indicates that North American Indians have just recently developed an advanced calendar.

gmat_perfect wrote:A "calendar stick" carved centuries ago by the Winnebago tribe may provide the first evidence that the North American Indians have developed advanced full-year calendars basing them on systematic astronomical observation.

(A) that the North American Indians have developed advanced full-year calendars basing them
(B) of the North American Indians who have developed advanced full-year calendars and based them
(C) of the development of advanced full-year calendars by North American Indians, basing them
(D) of the North American Indians and their development of advanced full-year calendars based
(E) that the North American Indians developed advanced full-year calendars based

[spoiler]OA: After discussion[/spoiler]

IMO E
First point - The evidence found is not of "North American Indians". Evidence is of calendar so rule out B and D.
Left with A, C and E.
"have developed" is not correct as the instance is of past. So rule out A.
D is passive + "basing them" is not correct here.

So left with E

A "calendar stick" carved centuries ago by the Winnebago tribe may provide the first evidence that the North American Indians have developed advanced full-year calendars basing them on systematic astronomical observation.

(A) that the North American Indians have developed advanced full-year calendars basing them
(B) of the North American Indians who have developed advanced full-year calendars and based them
(C) of the development of advanced full-year calendars by North American Indians, basing them
(D) of the North American Indians and their development of advanced full-year calendars based
(E) that the North American Indians developed advanced full-year calendars based

The splits:

See the following sentence:

They have developed the concepts basing them on X.

--> It means that "they are based on X". So, the meaning of the option A becomes "North American Indians are based on systematic ..". Eliminate A.

They have developed X and based them on Y.

--> It means that "they based them on Y"; therefore, the meaning of the option B becomes "NA Indians based them on systematic ...". Eliminate B.

COMMA + VERBING: modifies the entire preceding clause. in the option C, COMMA + Basing does not have a clause before COMMA. Eliminate C.

Evidence of X and Y:

--> It means that they have found the evidence of X and Y. The intended meaning of the sentence is not so. See the option D.
.....may provide evidence of the North American Indians and their development of advanced full-year calendars based.--> It means that the calendar stick provide of both NA Indians and their development of calendars; therefore, option D changes the meaning of the sentence. Eliminate D.

[spoiler]Answer: E[/spoiler]

gmat_perfect wrote:A "calendar stick" carved centuries ago by the Winnebago tribe may provide the first evidence that the North American Indians have developed advanced full-year calendars basing them on systematic astronomical observation.

(A) that the North American Indians have developed advanced full-year calendars basing them
(B) of the North American Indians who have developed advanced full-year calendars and based them
(C) of the development of advanced full-year calendars by North American Indians, basing them
(D) of the North American Indians and their development of advanced full-year calendars based
(E) that the North American Indians developed advanced full-year calendars based

[spoiler]OA: After discussion[/spoiler]

Option A has tense issues. We don't need 'Have developed' -- Past perfect.

The calendar was developed centuries ago -- so we need simple past here.

Option B and option D changes the intended meaning of the sentence. Evidences of the development of the calendars were found and NOT of the North American Indians.

Option C is wordy + basing them reflects that the North American were based on astronomical observation... this is what I understood.

OPTION E is the right choice. Correct, Clear and Concise.

Good explanations I went for E as well.