If $$2x - y + 1 = 0$$ is a tangent to the hyperbola $$\frac{x^2}{a^2} - \frac{y^2}{16} = 1$$, then which of the following CANNOT be sides of a right angled triangle?

A

a, 4, 1

B

a, 4, 2

C

2a, 8, 1

D

2a, 4, 1