How could an advertiser determine the most profitable keywords within a campaign?

How could an advertiser determine the most profitable keywords within a campaign?

A) Identify the keywords with the highest clickthrough rates (CTRs).
B) Compare the costs accrued by each keyword with the conversion data
for that keyword.
C) Compare the total clicks to total conversions for each keyword in
the account.
D) Identify the keywords with the …

Answer: B