GMAT Sentence Correction (SC) | Re: In 1988, the Council on Economic Priorities began publishing

In 1988, the Council on Economic Priorities began publishing Shopping for a Better World, with the simple thesis of consumers having the power to change companies by the simple expedient of refusing to buy.
A. with the simple thesis of consumers having
B. which had the simple thesis of consumers having
C. where the thesis was simple: consumers having
D. with a thesis that is a simple one: consumers have
E. whose thesis was simple: consumers have