Hi! It will be a pleasure to help you finding the solution to this problem, so let's solve each part:
PART 1.
Finding the correct expression.
Correct answer:

From the problem, we know the following data of the problem:
- Laval parked at the beach.
- Laval paid a fixed price of $4 for a pass.
- Laval paid $1.50 for each hour.
Our goal is to find the the expression for the total cost for parking at the beach for h hours. So:
Step 1: Since we have a fixed price, this value will appear in our expression:

Step 2: Since Laval paid $1.50 for each hour, this can be represented as the following expression:

Finally, we can write total cost (C) as the sum of these two expressions:

Finally, our correct option is A:

PART 2.
Finding h.
Correct answer:
5 hours
Here we have to find how many hours Laval spent at the beach knowing that he paid a total amount of $11.50. From the previous part, we know that our expression is:

Finally, he spent 5 hours at the beach