Answer: Key aspects of his accounts, including statistics, settings, and industry trends.
Explanation:
The options to the question are:
a. Testing and reporting on the speed of Brian’s websites
b. Key aspects of his accounts, including statistics, settings, and industry trends.
c. Judging ad popularity on social media
d. Comparing Brian’s sales with ad serving data.
Optimization score simply runs from 0% to 100% and it is simply an estimate that'll tell am individual or firm how well their Google Ads account will perform. Having 100% means that the account will be able to perform at full potential.
Based on the information given in the question, Brian's optimization score is based upon Key aspects of his accounts, including statistics, settings, and industry trends.