A function $f(x)$ has a power series expansion $\sum_{n=0}^{\infty} c_n x^n$ centered at $x = 0$ with radius of convergence $R = 4$. When we rewrite the same function as a power series centered at $x = 2$, i.e., $\sum_{n=0}^{\infty} d_n(x-2)^n$, which statement must be true about the new radius $R'$?