Answer:
i need options, since this is a broad question
Explanation:
I think the correct one is B
we know that
the surface area of the top of the water
is calculated with the formula of the area of a circle

Step 1
Find the radius of the water tank in the middle of the tank
by proportion

so
For h=5 m
the radius is equal to r=1.5 m
Step 2
Find the surface area


therefore
the answer is
the surface area of the top of the water is 