I've included a photo of the question my homework asks, and the answers it offered to choose from. The correct answer is D according to my homework, but I'm really struggling to understand why it wasn't answer A. Any insight would be greatly appreciated!

How did you determine the average fixed cost?

The table given below shows the short-run costs for a perfectly competitive firm that produces Good X. At the loss-minimizing output, Table 8.2 Units Manufactured Price (P) Total Cost Average Variable per day(Q) (TC) Cost (AVC) $15 $22.50 $15 $37.50 15 2 $15 $49.50 13.5 $15 $60 12.45 $15 $69 11.7 $15 $81 11.7 6 $15 $94.50 9 7 $15 $109.50 12.45 8 $15 $127.35 13.05 9 $15 $147 13.8 10 $15 $169.50 14.7 11 $15 $198 15.9