So what about the following argument? Is this valid?

A→B

A ←s→ C

B←s→ C

To my understanding of the LSAT, you are NOT supposed to include any outside knowledge. So, for Q2, I didn't necessarily infer based on previous knowledge. To make it tangible, I put "not in "interglacial periods" vs. "interglacial periods" since those are what I understood as the implications of the comparative claim.

For the first one, why wouldn't "grant" be the predicate-object?

What makes an assumption 'reasonable'? I am struggling with the definition and criteria of the term reasonable