Help me with 9 plz thanks

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.

Suppose a pendulum is l meters long. the time,t,in seconds that it tales to swing back and forth once is given by t=2.01

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?