The C2 Corvettes from 1963-1967 were all similar in general styling for the generation except for some obvious styling differences, such as the '63 split window. Also front fender gills changed from horizontal to vertical in 1965, and 1967 gills were unique unto themselves for that particular model year. But some years were almost identical except for some subtle changes. For instance, in this case, the 1965 and 1966 Corvettes.
The 1966 Corvette's styling was very similar to the previous model, except with the addition of the Corvette Script on the leading edge of the hood, a plated square mesh grill. Also, roof vents located just behind the driver and passenger doors had been both functional and non-functional in previous mid-year coupes, were now deleted completely.
The correct answer is: 1966