In the following set of words, which is different than the others?

Question

Quizplus · Accepted Answer

Sweet is an adjective, which means 'having the pleasant taste characteristic of sugar or honey'. It is not similar to the other words in the set, because they all describe flavors that are not sweet, but rather, sharp and intense. 
Bitter is an adjective, which means 'having a sharp, pungent taste or smell'. It is similar to the other words in the set (excluding 'sweet') because they all describe flavors that are not sweet, but rather, sharp and intense.
Sharp is an adjective that can be used to describe flavors, which means 'distinct in taste and clearly defined as acidic or intense'. 
Tart means 'sharp or acidic in taste'. 
Acidic is an adjective that can be used to describe flavors, which means 'sharp-tasting or sour; acidic' It is similar to the other words in the set (excluding 'sweet') because they all describe flavors that are not sweet, but rather, sharp and intense.

In the Following Set of Words, Which Is Different Than