Mathematics for IGCSE & O level - Number (Section 1 - No. 49)

Which set of numbers are all integers?

-2, 0, 1.5, 4

-3, 0, 5, 9

1/2, 2, 3/4, 7

-1, 0.2, 3, 5

Integers are whole numbers and their negatives. -3, 0, 5, and 9 are all integers.