PLS 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?

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