Fill in the blank with the correct Preposition:-

The gift was so beautiful that he was overwhelmed __________ joy.

with

The correct preposition to fill the blank is with.

Here's why:

• "With" indicates the feeling or emotion that overwhelmed the person.
• "For" suggests a reason or cause for the feeling, which is not the intended meaning in this context.
• "To" typically indicates a direction or recipient, and doesn't fit the context of the sentence.
• "In" is not commonly used to express emotions or feelings.

Therefore, "The gift was so beautiful that he was overwhelmed with joy." is the correct and grammatically accurate sentence.