AHSME 1991 Problem 15

A circular table has 60 chairs around it. There are $N$ people seated at this table in such a way that the next person seated must sit next to someone. What is the smallest possible value for $N$? $\text{(A) } 15 \text{(B) } 20 \text{(C) } 30 \text{(D) } 40 \text{(E) } 58$