[Q]: How does the sentence end?

Lawrence smoked cigarettes and Craig did not smoke, so

[A]: Lawrence had a very distinctive smoky smell.

[Q]: How does the sentence end?

The bagel shop sells muffins, but not donuts, because

[A]: muffins have a much higher profit margin.

[Q]: How does the sentence end?

Kayla always feeds the goldfish because Monica forgets to.

[A]:
Monica should be grateful the fish are still alive.