If ∑n=0∞anxn\sum_{n=0}^{\infty} a_n x^n∑n=0∞anxn has radius of convergence R=5R = 5R=5, what is the radius of convergence of ∑n=0∞anx2n\sum_{n=0}^{\infty} a_n x^{2n}∑n=0∞anx2n?
5
5\sqrt{5}5
25
Cannot be determined