Fill in the blank by choosing the suitable option:

This is the same book _________.

that you gave me last week.

The correct answer is Option (2) - that you gave me last week.

In the sentence "This is the same book that you gave me last week," the word "that" correctly introduces a relative clause that describes the book.

OTHER OPTIONS

• "what you gave me last week."  (Incorrect use; "what" is not suitable for introducing a relative clause about a specific noun.)
• "which you gave me tomorrow."  (Incorrect tense; "tomorrow" implies a future action, which doesn’t fit the context of "the same book.")
• "whom you gave me yesterday."  (Incorrect use; "whom" refers to people, not objects like a book.)