Answer:
a: 4
b: 5 is alone, p, -4p and 5p are in the same group, and 7q is alone
c: 2uv squared and -uv squared are in the same group. Everything else is alone.
Explanation:
4 is multiplied by y. Kinda self explanatory.
Even though p doesnt have a number before it, it still does. Variables always have coefficients, and if you can't see it, that means it's one.
uv squared is one of the terms, so any number before it makes it part of the group. Everything else is not similar, so you got your answer.
I don't know what grade you are in, but I'm guessing your in a low grade, so sorry if I was unclear.