Which sentence is grammatically correct?

The choice that is grammatically correct is selected because it accurately uses the word "too" to mean "also" or "as well." In this context, the sentence implies that the speaker wants ice cream in addition to something else, which is the intended meaning of "too." The use of punctuation is also correct with a comma preceding "too," enhancing the clarity of the sentence.

The other sentences contain various grammatical errors. For instance, the first choice incorrectly uses "two" (the number) instead of "to" (a preposition indicating direction or place). The third option incorrectly uses "too" where "too" is meant to describe an excessive quantity; "shorts" should not have “too” modifying it. Lastly, while the fourth choice is almost correct, it could be improved with punctuation depending on the surrounding text, but it functions in a complete and clear way without that context.