abstract algebra - Galois Group of $(x^2-p_1)cdots(x^2-p_n)$

For distinct prime numbers $p_1,...,p_n$, what is the Galois group of $(x^2-p_1)\cdots(x^2-p_n)$ over $\mathbb{Q}$?

This problem appears to be quite common, however my understanding of Galois theory is quite poor, and I have no idea how to do this problem.