need help pls !!A group of student scientists wanted to find out about the water in the drinking fountains at school. They wanted to answer this question: What is the quality of the water in the drinking fountains? The students measured the mineral content, the pH, the density and the clarity of the water.

Which of the following best explains the scientists' plans?

The scientists are making observations.

The scientists are conducting an investigation.

The scientists are conducting a controlled experiment.

The scientists are conducting both an investigation and a controlled experiment.

According to the question, a group of students want to know the quality of water in the drinking fountain and thus they conduct several tests which include checking the mineral content, pH, density and clarity of the water.

The best explanation of the student's plans is that they are conducting an investigation.

An investigation is when a person conducts a test to find out something or to make an obscure thing clearer.

The students are NOT conducting a controlled experiment because their tests were not done in controlled conditions where some variables were changed at a time and others were kept at constant.