They ask us the interval when f(c) (that is, on the y-axis) is greater than 0.
We analyze each answer option and obtain:
A: -2 < x < -1
when x is between -2 and -1, the y values are negative (less than 0)
B: 1 < x < 2
when x is between 1 and 2, the y values are positive (greater than 0)
C: 4 < x < 5
when x is between 4 and 5, the y values are negative (less than 0)
Therefore, the answer is the option B 1 < x < 2