Grockit: Corporate compensation

edirik wrote:Ever since the publication of an industry report on corporate compensation, which suggested supervisor’s salaries be determined based on the production of those whom they manage, many companies began to create elaborate scales and formulas to determine what the pay for management positions should be.

A. supervisor’s salaries be determined based on the production of those whom they manage, many companies began

B. supervisor’s salaries be determined by the productivity of those whom they manage, many companies began

C. that the salaries of supervisors be determined based on the production of those whom they manage, many companies have begun

D. that the salaries of supervisors be determined by the productivity of those whom they manage, many companies have begun

E. the salaries of supervisors be determined by the productivity of those whom they manage, many companies began

OA after some discussion.

edirik wrote:And the official answer is D

@Mitch, I totally agree with this explanation

Also, the sentence is not about production but about PRODUCTIVITY.

but about this one

determined based on is unidiomatic.

I thought that we can determine people's performance BASED ON something such as productivity. If it were "determined by", then I thought that "determined BY THE BOSS".

For example:

The score of people in Gmat is determined BASED ON Quant and Verbal performances.
The score of people in Gmat is determined BY Quant and Verbal performances.

Then, is it really the case that the former one is not idiomatic?