If the Universe is now expanding, why must it once have been a point?

I’m not sure about this question

Ive had this before. your answer would be d. hope this ya

Moles = mass/molar mass the molar mass of c20 = 12.011*20 = 240.22 g per mole therefore, the number of moles is 20 g / 240.22 g per mol = 0.0833 moles.

They adding another layer their bahaviors.