As well as heat and light, the Sun is the source of a continuous stream of atomic particles known as the solar wind.

(A)...
(B) Besides heat and light, also the Sun is the source of a continuous stream

(C) Besides heat and light, the Sun is also the source of a continuous streaming

(D) The Sun is the source not only of heat and light, but also of a continuous stream

(E) The Sun is the source of not only heat and light but, as well, of a continuous streaming

The OA is D

Can someone explain why C is wrong?