Graph the function f(x) = x4 − 7x3 + 12x2 + 4x − 12 using graphing technology and identify for which values of x the graph is increasing.

we have

The options of the question are

A. X:-3 to x:-2

B.x:-2 to x:-1

C. X:1 to x:2

D. X:2 to x:3

Using a graph tool

see the attached figure

The graph is increasing in the interval (-0.15,2) and the interval (3.4, ∞)

The graph is decreasing in the interval (-∞, -0.15) and the interval (2,3.4)

therefore

the interval (1,2) is included in the interval (-0.15,2)

the answer is the option

C. X:1 to x:2