If $$1 - x + x^2 - x^3 + \cdots + x^{20}$$ is rewritten in the form $$a_0 + a_1(x-4) + a_2(x-4)^2 + \cdots + a_{20}(x-4)^{20}$$, where $$a_0, a_1, \ldots, a_{20}$$ are all real numbers, the value of $$a_0 + a_1 + a_2 + \cdots + a_{20}$$ is

A

$$\frac{5^{21}+1}{6}$$

B

$$\frac{5^{21}-1}{6}$$

C

$$\frac{5^{20}+1}{6}$$

D

$$\frac{5^{20}-1}{6}$$