Explanation:

- The word "offbeat" often means unconventional or unusual.

- Option 1: Conventional is something traditional or usual. It serves as an antonym to "offbeat" as it represents common norms or practices.

- Option 2: Weird implies something strange or unexpected. It aligns more closely with "offbeat."

- Option 3: Freaky also suggests something peculiar or odd, similar to "offbeat."

- Option 4: Unique indicates being one of a kind, which is not directly opposite to "offbeat" but shares the sense of being different.

The correct antonym is: Option 1: Conventional