A researcher is interested in the effects of watching videos just before bed on the quality of sleep. He has decided to test the claim "Watching 1 hour of video just before going to bed reduces the number of minutes of REM sleep by more than 10%. Which of the following data collection processes would be appropriate? Select only one answer choice. Select the correct answer below:

A. Choose a random sample of people and ask them how many hours of video they watched last night and how much REM sleep they had.
B. Choose a random sample of people. Randomly select half of them and have them watch one hour of video just before going to bed, and then monitor their sleep. Have the other half not watch any video and monitor their sleep.
C. Choose a random sample of people. On multiple randomly selected nights, randomly assign each person to either watch one hour of video or not watch video and monitor their sleep.
D. Choose a random sample of people. On multiple randomly selected nights, measure the amount of video they watch and monitor their sleep.