The answer is D) Seventh and eighth grade students at the school preferred an eagle mascot.
This is because both Tiger and Eagle had 40 votes, so it couldn't be A) or B), as they both had the same number of votes. It also couldn't be C) because more fifth and sixth grade students voted for tiger than eagle. It could only be D) as more seventh and eighth grade students DID actually vote for the eagle mascot rather than the tiger mascot.