Space is expanding not stretching so the answer is c.

If what you said was real you would also be getting taller, wider, fatter because you would also be stretching you and earth are you are both in timespace as well.

Imagine you in a ballon and its being blown up the walls are moving out but nothing is changing in the ballon.

For us the walls for timespace are racing out into the nothingness so space is getting bigger and bigger.

Assuming there are no constraints, which I can not give you a scientific guarantee of, eventually the universe will become a bleak empty place and when we look up at the heavens there will be few stars as the matter of the universe will be vastly spaced out.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.