Nuno purchased five crypto coins for $1000 in October 2020. He sold two of the coins for $375 in May 2021. He later sold the remaining three coins for $720 in September 2021. What is his net gain or loss on the coins?

a: $25 short term loss.

b: $95 short term gain.

c: $120 short term gain.

d: $145 short term gain.