I also think it is the first one, but I am not entirely sure.
The three estates of Medieval Europe were Church, Nobility, and Peasantry. The clergy were the people who performed the religious duties and they were in the Church estate, therefore the answer is A.
A. the amount of time they spent building the wall
I think the answer is A, when I looked at the picture and did some research, I found that the wall is 70 miles long so it's pretty obvious that they spent a lot of time making it in ancient old times.
The annihilation of European Jews
