Find a formula for the nth term of the sequence.1,

1/4,

1/9,

1/16,

1/25,

... (reciprocals of squares with alternating signs)

a. a_n=(-1)^n^2^2

b. a_n=(-1)^n+1^2 c. a_n=(-1)^n^2

d. a_n=(-1)^2n+1^2

Find a formula for the nth term of the sequence. 16 25 . .. (reciprocals of squares with alternating signs) 2 (-1) OA. an = 2 n (-1) +1 OB. a= n (- 1)" OC. as 2 n 2n + 1 (-1) OD. an= 2