Final answer:
A yacht is generally considered a yacht if it is more than 90 feet long. Therefore, the correct answer is D) 90.
Step-by-step explanation:
In English, the subject of this question relates to the definition of a word and its usage. In this case, the word in question is "yacht."
A yacht is generally considered a yacht if it is more than 90 feet long. Therefore, the correct answer to the question is D) 90.