Which of the following is an example of how a scientist might use a model?
a) A stopwatch is used to time the rate of a chemical reaction
b) The end of a slinky is moved vertically up and down to simulate a wave
c) A microscope is used to magnify a group of cells on a slide
d) A wrench is used to tighten a nut onto a piece of wood

P.S.- This is Science not Chemistry