Problem: Amy was better at learning than Carrie, so

My choice: Amy didn't have to worry about failing the test.

Problem: Christine is a faster driver than Rachel because

My choice: Christine is always in a hurry to get everywhere.

Problem: Kayla made cornmeal porridge in the instant pot while Felicia tried to make it in the microwave,

My choice: Felicia was less advance.

Problem: The contagious disease was passed to Brett and not Steven because

My choice:
Brett has a weak immune system.