What is the prime factor of 112?

Question

$\begin{array}{11} (a)\; 2 \times 2 \times 7 \\ (b)\; 2 \times 2 \times 2 \times 7 \\ (c)\; 2 \times 2 \times 2 \times 2 \times 2 \times 7 \\ (d)\; 2 \times 2 \times 2 \times 2 \times 7 \end{array}$