In any spontaneous process, the __________ free energy decreases.

Answer: Option C

For any spontaneous process $$dG⩽0,dA⩽0$$
And usually spontaneous process takes place when there are finite differences so, the process will be usually irreversible.
Hence $$dG<0\&dH<0$$
So, free energy goes on decreasing and when the finite difference becomes infinitesimal difference it becomes constant.