The sum of three lengths of a fence ranges from 45 to 60 inches. Two side lengths are 9 and 18 inches. If the length of the third side is x inches, write and solve a compound inequality to show the possible lengths of the third side.
a. 9 ≤ x ≤ 18
b. 18 ≤ x ≤ 33
c. 36 ≤ x ≤ 42
d. 45 ≤ x ≤ 60