6×10⁸ is how many times as large as 2×10³

Which of the following situations represents a linear relationship? a. theresa increases the distance she runs by 0.1 miles every week. b. the volume of a box depends on the length of box. c. the amount of money in a bank account increases by 1 percent each year. d. the population of a town doubles every 5 years.

Multiply. write your answer in simplest form. 3/8 x 5/7

Having a hard time understanding this question (see attachment).