Thats a rectangle .........
A discrete variable is a variable which may take only certain discrete values; for example the number of people in a household is a discrete variable which may have the value 1, 2, 3, etc. but cannot have intermediate values such as 1.473 or 3.732.
Choice d) can be represented by a discrete probability distribution, the other choices cannot be so represented.
Substitute the numbers in the equation:

Since L=5in, W=4in and H=8in:

Therefore, the volume is equal to 160 inches cubed.