Fill in the blank with the appropriate preposition:

I'm good ...... Football.

at

The correct answer is OPTION 2-- at.

The preposition at is used to indicate skill or proficiency in something. In this case, I'm good at football, which means that I am skilled or proficient at playing football.

The other options are incorrect.

• In is used to indicate location or position, but it is not the most appropriate preposition to use in this case.
• With is used to indicate association or cooperation.
• On is used to indicate movement or placement above something, but it is not the most appropriate preposition to use in this case.