Concept:The nth term of an AP is a+(n−1)d.Explanation:Given AP: 64,60,56,52,…First term a=64, common difference d=60−64=−4.We need the term that equals zero, so set a+(n−1)d=0.64+(n−1)(−4)=064−4(n−1)=04(n−1)=64n−1=16n=17Answer:The 17th term is zero.Option B corresponds to 17.