Answer:
Option D.
Explanation:
As per given statements we see the time of Sasha practice it increases by a fixed factor of '2' or we can say Sasha's time is multiplied by '2' every week.
When we see the time of Mona's practice, it increases by 10 mins every week. hence there is a addition of a fixed number '10'.
so option D is correct which says Sasha's method is exponential because it increases by a fixed factor, and Mona's method is linear because it increases by a fixed number.