plz help

Two students are comparing scientific experiments to investigations. They came up with the following ideas.

Student A: Testing plant growth in different types of soils
Student B: Comparing the water level in a lake during different times of the year

Which student gave an example of a scientific experiment? (5 points)

Student A because it requires experimental and control groups

Student B because it requires a hypothesis

Student A because it is preferably done in natural settings

Student B because it is preferably done across a long period of time