Alysha wants to test the effect of different materials on the melting rate of ice. She finds the initial mass of four pieces of ice. She then covers three pieces with either tinfoil, plastic wrap, or paper. The fourth piece is left uncovered. After 30 minutes, Alysha calculates the final mass of each piece of ice to determine which melted the fastest. What are the independent and dependent variables in Alysha's experiment?

Explanation:

An independent variable is a variable that represents a quantity that is being manipulated in an experiment

In the given conditions, three pieces of ice are covered with either tinfoil, plastic wrap or paper and fourth piece is left uncovered so it is clearly visible cover material is being changed for different ice piece hence independent variable is the type of cover material

A dependent variable represents a quantity whose value depends on how the independent variable is manipulated

In the given conditions, final mass of each piece of ice is calculated where three pieces of ice are covered and one is left uncovered therefore the final mass of ice piece is dependent on the type of cover material hence dependent variable is mass of the ice

i think the answer is b.