Question

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Explanation:

For the first question: In experimental research, the experimental group is exposed to the variable being tested (here, music during the memory task), while the control group is not. The group listening to music is the one receiving the experimental treatment.
For the second question: Random assignment means selecting participants in a way that every individual has an equal chance of being chosen, with no bias. Rolling dice to pick seats is a random, unbiased method, unlike the other options which use non-random criteria (age, volunteering, skill).

Answer:

1. experimental group.
2. roll dice to select both a row of seats and a seat in that row, and do this four times.