Subject: mathqa
Question: each year for 4 years , a farmer increased the number of trees in a certain orchard by 1 / 4 of the number of trees in the orchard of the preceding year . if all of the trees thrived and there were 12500 trees in the orchard at the end of 4 year period , how many trees were in the orchard at the beginning of the 4 year period .
Option: 
A: 5120
B: 8119
C: 5117
D: 5113
Answer: A