To determine the possible third side of a triangle given two side lengths, we can use the triangle inequality theorem. This states that the length of any one side of a triangle must be less than the sum of the lengths of the other two sides and greater than the difference between the lengths of the other two sides.
Therefore, for a triangle with side lengths of 6.5 and 2.75 inches, the possible range for the third side length would be:
6.5 - 2.75 < third side < 6.5 + 2.75
3.75 < third side < 9.25
Out of the given options, only C.) 5.5 inches falls within this range, so the answer is C.