Answer:
My great-grandma (she's ninety-one) traveled alone to Denver.
Explanation:
Correct punctuation of a sentence is when the usage of the capital letters, punctuation signs are correctly and rightly used in the sentence. The use of the various signs show how or what the sentence can be/ is.
Among the options given in the question, the fourth/ last option is the correct way of punctuating the sentence.
The use of the quotation marks (" ") in option 1 is wrong.
In the second sentence, if the sentence is continuous and free flowing, a comma has to be placed right after grandma, so as to start or signify the dependent clause in the sentence.
Same case with option 3. A comma should be used after ninety-one to end the dependent clause.
Thus, the correct sentence is -
<u><em>My great-grandma (she's ninety-one) traveled alone to Denver. </em></u>
