the answer to your question would be A. replace y with 9. why?? well here is how you would solve this problem
1. 5+4y when y=9 (first plug 9 into the y's spot)
2. 5+4(9) then multiply 4 times 9 (that's what 4(9) means)
3. 5+36 then add
4. 41
the answer to the equation is 41 but the answer to your problem is A.