Examine the graph.

select each interval where the graph is decreasing.

a) -4 < x < -2

b) 2 < x < 3

c) -1 < x < 1

d) 3 < x < 4

A) -4 < x < -2
B) 2 < x < 3
D) 3 < x < 4

They, all are the answers except C.
Here, we can see the graph is decreasing at that instances. so, that is your answer!

Hope this helps!