**Answer:**

b. closed circles on 1 and 4 with arrows pointing outward

**Step-by-step explanation:**

Which of the following describes the graph of {x | x < = 1} u {x | x > = 4},

We have been given the following set;

x < = 1

This set comprises of real numbers that are less than or equal to 1;

(1, 0, -1, -2, -3, -4, .......... -∞)

On the other hand, the set x > = 4 comprises of real numbers that are greater than or equal to 4;

(4, 5, 6, 7, 8, 9, ........∞)

The symbol ∪ means a union of sets. That is the set of numbers that belong in either or both sets;

{x | x < = 1} u {x | x > = 4} is same as writing;

(1, 0, -1, -2, -3, -4, .......... -∞) ∪ (4, 5, 6, 7, 8, 9, ........∞)

Therefore, the solution set will be closed circles on 1 and 4 with arrows pointing outward