A-b is the answers
...........
keeping in mind that template, let's take a looksie
It's y such that y ≤ 3
{y|y≤3}
Look at the maximum of the values of y (it's 3) now look at the minimum (-infinity) so y is less than or equal to 3.
Let's call them B, M, C, L
We'll have (without reapeating):
B,M
B,C
B,L
M,C
M,L
C,L