so
an=n^2-a(n-1)
the nth term is equal to n^2-previous term
5th term=5^2-previous term
14.25=25-previousterm
previousterm=10.75=4th term
4th term=4^2-previous term
10.75=16-previous term
previousterm=5.25=3rd term
3rd term=3^2-previous term
5.25=9-previous term
3.75=previus term=2nd
so we see it is 2nd option