I think I got the answer right but before I submit it can anyone tell me if I'm correct

Answer:
A. (100·-m) + (45·m)
Step-by-step explanation:
The answer that you selected is wrong. The correct answer is A which is
V = (100·-m) + (45·m) because stock A decreases per sock so your going to multiply 100 times -m because it is decreasing so it will be negative
Then it will be 45*n because it increase per number of stocks so you multiply 45 which is the number of stocks times n