How many positive integers less than $50$ have an odd number of positive integer divisors?
$\text{(A) } 3\quad \text{(B) } 5\quad \text{(C) } 7\quad \text{(D) } 9\quad \text{(E) } 11$
Divisors come in pairs, unless there is an integer square root, so we just need the perfect squares below $50$. There are $7$, so $\fbox{C}$