Intervals
A numeric interval consists of a set of numbers (in case they are whole or integer numbers) or a range of numbers that fulfill a rule or condition.
We are given a graph where the interval (-∞,-2] can be identified. This means the numbers that are less or equal to -2 belong to the solution.
From the numbers given in the options, we should only select those who are less than or equal to 2:
A. -2
D. -4
E. -10
Options B and C are not correct because 0 and 5 don't lie on the solution interval