Sentence Correction

Prospecting for gold during the California gold rush was a relatively easy task, because of
erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the surface
by volcanic activity put gold literally within reach for anybody with a pan or shovel.

A. because of erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to
the surface by volcanic activity put gold literally within reach for
B. because of erosion, prehistoric glacier movement, and volcanic activity that thrust ancient, goldbearing riverbeds to the surface, and putting gold literally within reach of
C. owing to erosion, prehistoric glacier movement, and volcanic activity that had thrust ancient,
gold-bearing riverbeds to the surface, and putting gold literally within reach of
D. since erosion, prehistoric glacier movement, and volcanic activity that thrust ancient, goldbearing riverbeds to the surface, putting gold literally within reach for
E. since erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the
surface by volcanic activity put gold literally within reach of

OA E

AnjaliOberoi wrote:Prospecting for gold during the California gold rush was a relatively easy task, because of
erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the surface
by volcanic activity put gold literally within reach for anybody with a pan or shovel.

A. because of erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to
the surface by volcanic activity put gold literally within reach for
B. because of erosion, prehistoric glacier movement, and volcanic activity that thrust ancient, goldbearing riverbeds to the surface, and putting gold literally within reach of
C. owing to erosion, prehistoric glacier movement, and volcanic activity that had thrust ancient,
gold-bearing riverbeds to the surface, and putting gold literally within reach of
D. since erosion, prehistoric glacier movement, and volcanic activity that thrust ancient, goldbearing riverbeds to the surface, putting gold literally within reach for
E. since erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the
surface by volcanic activity put gold literally within reach of

OA E

A: Prospecting was a relatively easy task...because of riverbeds
Not the intended meaning: the RIVERBEDS themselves did not cause prospecting to be easy.
Eliminate A.

B: that thrust...and putting
C: that had thrust...and putting
A conjunction such as and must connect PARALLEL FORMS.
Here, putting is not parallel with the preceding verbs (thrust and had thrust).
Eliminate B and C.

D: since erosion...that thrust ancient, goldbearing riverbeds to the surface...putting gold literally within reach
Here, since serves as a synonym for because.
When since serves this purpose, it must be followed by a CLAUSE.
A CLAUSE contains both a subject and a verb.
In D, the phrases in red serve as MODIFIERS.
As a result, erosion (subject) lacks a verb, with the result that since is not followed by a complete clause.
Eliminate D.

The correct answer is E.