The essence of the passage: advertising agencies have modified a strategy developed for political campaigns.
This undermines C, which says that campaign managers transformed political campaigns by making increasing use of strategies borrowed from corporate advertising campaigns.
Stolyar, C talks about campaign managers .
We are talking about Advertising Agencies, isnt it.
The argument does not do anything to undermine C. both of them are equally possible.
Tricky, dont u think?
Even i picked C..but A is indeed the best answer.
This strategy aims to provide clients with free publicity and air time by designing an advertising campaign that is controversial, thus drawing prime-time media coverage and evoking public comment by officials.
This quote tells us that the advertisment's aim is to provide CLIENTS with free publicity. so it does not deal with the Audience at all. its target is publicity.
But A tells us that the use of an advertisement can ONLY be determined by the degree to which it can persuade its AUDIENCE.
A is the best answer