Step 1: Identify common prepositions with "good''
- The phrase "good at'' is commonly used to indicate skill in an activity.
Step 2: Analyze options
- (A) "at'' correctly fits to show proficiency.
- (B), (C), and (D) do not fit this phrase properly.
Step 3: Conclusion
Option (A) "at'' is the correct preposition to use with "good.''