AMC 12 2020b Problem 4

The acute angles of a right triangle are $a^{\circ}$ and $b^{\circ}$, where $a>b$ and both $a$ and $b$ are prime numbers. What is the least possible value of $b$?

$\textbf{(A) }2 \textbf{(B) }3 \textbf{(C) }5 \textbf{(D) }7 \textbf{(E) }11$