Final answer:
Data set a is for the uniform line of charge and data set b is for the uniformly charged sphere.
Step-by-step explanation:
The correct answer is option 3: Data set a is for the uniform line of charge and data set b is for the uniformly charged sphere.
In data set a, the left sphere is negatively charged and is attracted by the positively charged sphere, which is a characteristic of a uniform line of charge.
In data set b, the left sphere is positively charged and is repelled by the positively charged sphere, which is a characteristic of a uniformly charged sphere.