Use the Following to Answer Questions

Use the following to answer questions
Scenario I
Scenario I is based on fabricated data inspired by the following study:
Kahn, M., Fridenson, S., Lerer, Bar-Haim, Y. & Sadeh, A. (2014) . Effects of one night of induced night-wakings versus sleep restriction on sustained attention and mood: a pilot study. Sleep Medicine, 15, 825-832.
Effect of Sleep Deprivation on Attention Study
The purpose of this study was to examine whether sleep interrupted by frequent waking affects a person's mood and attention. Forty women and 21 men participated in a one-factor within-subjects design that consisted of two treatment conditions. In the control condition participants had eight continuous hours of sleep. In the experimental condition participants also had eight hours of sleep, but it was interrupted every two hours. After each treatment the participants' mood was assessed using the Profile of Mood States (POMS) and their attention was assessed with an Online Continuous Performance Test (OCPT) . The participants also recorded how they felt using a behavioral diary. The results revealed a significant difference in participants' mood and attention across the two treatment conditions. As predicted, when sleep was interrupted participants reported feeling more depressed than when they received eight hours of continuous sleep. The data also indicate that when sleep was interrupted the participants made more errors on the OCPT than when they received eight hours of continuous sleep. These quantitative data support the behavioral diary entries of the participants. The results of this study indicate that sleep deprivation has emotional and cognitive consequences.
-(Scenario I) The study described in Scenario I required participants to volunteer two nights of sleep. What might the researchers have done to minimize the attrition rate?

A) provide a monetary incentive for each night and a bonus incentive for participating in both nights
B) increase the number of days between each sleep condition
C) ensure consistency in the way behavior was assessed so participants knew what to expect the next time they were studied
D) all of the above