Marketing companies monitor and evaluate the impact of their advertising on their target audiences by investing in research to measure the result of their advertising campaigns. Usually, the most important information to discover is
a. the target audience's awareness of the brand name
b. the frequency that the target audience sees/hears the ads
c. advertising awareness of familiarity of the key ad message points by the target audience(s)
d. the amount of sales the ads generated from the target audience