Step-by-step Answer::
"Each month, the balance in the account increases by 0.25%"
means F(n)=F(n-1)*1.0025
"Elaine deposited $50 into a bank account."
means F(0) = 50
So a recursive definition is
F(n) = F(n-1)*1.0025 for n=1,2,3,4... and F(0)=50
Symbols used in the actual answer choices may differ, but with the same principle.