Universe Expansion Question

My teacher asked this question and said the answer is B, but i dont really understand why could you explain it?
The Larger the mass of the known Universe the _______ the time elapsed since the Big Bang
A. Longer
B. Shorter
C. The Same

I thought the Universe was constantly expanding so the larger the universe the longer since the big bang, can you explain why I am wrong? Thank you.

The key word in the question is "mass." What you're thinking about is "space." Due to the expansion of *space* the time elapsed since the Big Bang would be longer if there was more space, which is what you said.

I'm mystified about your teacher stating that how a larger *mass* content of the known universe would equal less time since the Big Bang. Only thing I can come up with has to do with the dual nature of mass and energy, as shown by the Einstein equation E = MC² Maybe teacher is thinking that there would be more mass in the earlier universe because that mass hasn't yet been converted into energy.