Answer:
Third and fourth choice
Explanation:
The problem declares two variables: y is total cost and x is hours. You can observe the choices -- substitute in hour's value and compare if it's true.
A
Since the first choice says that the total cost is $1.50 for 1 hour, substitute x = 1 in:

Therefore, parking for 1 hour is $3.60, not $1.50. Hence, the first choice is false.
B
The second says that the total cost is $4.20 for 2 hours, do the same thing; substitute in x = 2:

Therefore, for 2 hours, it's $5.70. Hence, the second choice is false.
C
The third says that it's $7.80 for 3 hours. Substitute in:

$7.80 after evaluation as said. Hence the third choice is correct.
D
The fourth says that it's $12.00 for 5 hours:

$12.00 after evaluation as said. Hence the fourth choice is also correct.
Therefore, correct answers are third and fourth choice.