Answer:
The correct answer is given by the option c. 2 × 2 × 3.
Explanation:
The experiment has three variable involved namely temperature of the room, difficulty of material and amount of material.
For temperature of the room there are two parameters namely warm or cold.
For difficulty of material there are two parameters namely easy or difficult.
For amount of material there are three parameters namely low or moderate or high.
Thus the first and second variable has 2 parameters and the third has 3 parameters.
Therefore the best suited statement that applies to the design of this study is given by the option c. 2 × 2 × 3.