The answer is D
The student cannot find out the total number of cars with any particular attribute from conducting a survey. He would have to examine all the cars in his town for that, not just sample them. He can’t find out a nationwide percentage unless he has reasonable proof that his town is typical of the entire nation. He can, however, get a good estimate of the percentage of cars in his town that were made by a particular manufacturer. The more cars included in the survey, the more reliable the estimate becomes.