6th grade math help me please :)

Answer:
A. when evaluating the expression you multiply n by 3
Step-by-step explanation:
B.
1. n = 2; 3n + 7
step 1: multiply 3 (2) which will give you 6
step 2: add 6 + 7 which is 13
2. n = 5; 3n +7
step 1: multiply 3(5) and your answer is 15
step 2: add 15 + 7 and your final answer is 22