Question

which of the following sentences is punctuated correctly? she has a sixty-year-old grandmother. she has a sixty year old grand-mother. she has a sixty- year old grand mother. she has a sixty year-old grand-mother.

Explanation:

To determine correct punctuation:

1. Compound adjectives (like "sixty - year - old") use hyphens between words.
2. "Grandmother" is one word, no hyphen or space in between.
3. "Sixty" is a number, not a proper noun, so it should be lowercase.

The first option "She has a sixty - year - old grandmother." follows these rules: hyphens in the compound adjective, correct spelling of "grandmother", and lowercase "sixty".

Answer:

A. She has a sixty - year - old grandmother.