Question 2 (6 points) (06.05 MO) Justin is planning his science fair project. He wants to measure how oxygen levels affect the rate of photosynthesis in plants. Is this an example of a scientific investigation or an experiment? (5 points) O a An experiment because it tests a cause and effect relationship Ob An experiment because it does not ask a testable question OC An investigation because it uses only observations Od An investigation because there is a control group​