The lateral area of the shape is the sum of the area of all lateral faces.
The area of the lateral face that is rectangle with sides 5 mi and 2 mi is
\(A=5\cdot 2=10\ mi^2.\)
As you can see the shape has all four lateral faces of the same rectangular form with the same sides lengths, therefore,
\(LA=4A=4\cdot 10=40\ mi^2.\)
Answer: correct choice is B.
