I think you have to follow someone and ask them to be your tutor.
Answer:
Option D.

Step-by-step explanation:
The area of the circular bases is:

Where
is the radius of the circle
Then


The area of the rectangle is:

Where

b is the width of the rectangle and
is the length
Then the area of the rectangle is:


Finally the total area is:


Answer: c
hope this helps!
$21 because 3$x$7(numbers of days in a week)is $21. I hope this helps :)