Answer:
The answer is option D: the advertiser is bidding $0.70 between 9 pm-12 am on weeknights.
Explanation:
The normal bid is $0.40 and the bid multiplier is 75%.
This amount becomes:

= $0.70 (OPTION D)
So, the advertiser is bidding $0.70 between 9 pm-12 am on weeknights.