Must be true

[crackgmat007]

If d > 0 and 0 < 1 - (c/d) < 1, which of the following must be true?
I. c > 0
II. c/d < 1
III. d^2 + c^2 > 1

(A) I only
(B) II only
(C) I and II only
(D) II and III only
(E) I, II, and III

Pls explain. Tx. OA - C

[mehravikas]

1. C has to greater than 0 otherwise 1 - c/d < 1 will be false

because 1 + c/d will always be greater than 1

2. c / d < 1 - again if c/d is greater than 1 then 0 < 1 - c/d will not hold true

3. d^2 + c^2 > 1

d = 1/2, c = 2/3

1/4 + 4/9 = 25/36 < 1 i.e. statement 3 is not must be true

Hence C.