Which statement is a hypothesis these students might be using in their experiment?

A this experiment tests how the speed of a toy car changes with the steepest of the ramp .

B it’s fun to see how fast the cars roll down the steepest ramp.

C if a toy car is down ramps of different steepest it will roll fastest on the steepest ramp .

D will a toy car roll faster down a steeper ramp ?

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.