Thank you, this explained it well!

a and b are positive integers such that 4<a+b<6 and |a−b|=1

A+B has to be 5 since A & B Are integers and the absolute value equation has to be equal to 1.

Two numbers that satisfy this are 2 and 3.

Now:
The volume of a cylinder with radius a and height b
The volume of a cylinder with radius b and height a

We don't know which is 2 and which is 3. The one with Radius 3 will be greater than Radius 2.

Answer D.

For completeness:

Pi(3^2)*2 = 18pi
Pi(2^2)*3= 12pi

$a + b = 5$

So, we can have $a = 1, 2, 3,$ or $4$ and $b = 4, 3, 2,$ or $1$

Also, $|a - b| = 1$

i.e. $|1 - 4| = 1$
$|2 - 3| = 1$
$|3 - 2| = 1$
$|4 - 1| = 1$

Col. A: $πa^2b$
Col. B: $πb^2a$

Dividing both sides by $πab$:

Col. A: $a$
Col. B: $b$

When $a = 2$ and $b = 3$, Col. A < Col. B
When $a = 3$ and $b = 2$, Col. A > Col. B

Hence, option D