A geologist fills three identical funnels with three different sizes of sandstone. Then, the geologist pours 500 mL of water into each funnel and measures how long it takes for the water to stop draining out of the bottom of the funnels.

A biologist cuts an African violet leaf into six equal-sized pieces. Then, the biologist carefully places the cuttings on six different petri plates, each filled with a different substance, and monitors the growth of the cuttings over the next several weeks.

A physicist places three identical glass rods in different beakers, each filled with a different liquid. Then, the physicist measures the angle of refraction in each scenario.

Which of the following statements is true based on the above information?
A.
Geologists, biologists, and physicists are only able to gather data through laboratory experiments.
B.
Variables and conditions cannot be controlled during a laboratory experiment.
C.
Laboratory experiments are a useful form of scientific investigation in many different fields of science.
D.
Physicists do not perform laboratory experiments as often as biologists and geologists.