Final answer:
Danielle is currently 3 years old.
Step-by-step explanation:
Let's say Danielle's age is x. According to the given information, Roberta is 6 times Danielle's age, so Roberta's age is 6x. In 12 years, Roberta will be 6x + 12 years old and Danielle will be x + 12 years old.
The question states that in 12 years, Roberta will only be 2 times Danielle's age. So, we can write the equation 6x + 12 = 2(x + 12). Solving this equation will give us the value of x, which is Danielle's current age.
6x + 12 = 2(x + 12)
6x + 12 = 2x + 24
4x = 12
x = 3
Therefore, Danielle is currently 3 years old. Therefore, the answer is option a. 2 years.