Concept: The missing word should describe a quality of the car that is questioned after praising its appearance.
Explanation:The sentence says the car is “very attractive” but the speaker has doubt about something.
The word must logically refer to how well the car lasts or withstands use over time.
“Durability” means the ability to endure wear, pressure, or damage.
This fits perfectly because a car can look good yet still be weak in build quality.
“Longevity” refers to long life, but “durability” is the more natural and precise choice for a car’s physical strength.
Thus, the best option is C. durability.
Answer: C. durability