In this question , the surface area is given which is 156 pi and a diameter of 12 in .
Radius is half of diameter, so radius is 6 in .
Now we use the formula of surface area of cylinder which is
[tex] Area = 2 \pi r^2 + 2 \pi r h [/tex]
[tex] 156 \pi = 2 \pi (6)^2 + 2 \pi *6*h [/tex]
Dividing both sides by 2 pi
[tex] 78 = 36 + 6h [/tex]
Subtracting both sides by 36,
[tex] 42 = 6h
\\
h = 7 in [/tex]
Correct option is B
