Answer:
Option A is correct.
Explanation:
Given: A Dot Plot
We need to find Number of more people who started babysitting when they were 13 rather than 12.
Number of people who started baby sitting when they were 12 year old = 3
Number of people who started baby sitting when they were 13 year old = 6
Number of more people who started babysitting when they were 13 rather than 12 = 6 - 3 = 3
Therefore, Option A is correct.