S.D. is 1.96 the confidence limit is-

Ref:Parks 23rd edition pg 849. SD = 1 : confidence limit = 68% SD = 2 : confidence limit = 95% SD = 3 : confidence limit = 99.7% Here , SD= is 1.96, (between 1and 2) So, confidence limit will be between 68% and 95%, but more close to 95%. So answer is 95%