Gerald Has Restricted His Calorie Intake While Continuing to Exercise

Gerald has restricted his calorie intake while continuing to exercise, and has been losing 1.5 pounds per week. However, when he weighs himself at the end of week 4, he notices he has not lost any weight since last week. What does this likely mean?

A) Gerald's internal thermostat has slowed down his metabolism to prevent fat loss.
B) Gerald is eating in his sleep at night as a response to deprivation.
C) Gerald's body is retaining water temporarily as part of the fat-burning process.
D) Gerald needs to reduce his calorie intake by an additional 500 calories a day.
E) Gerald needs to increase his calories a small amount to prevent ketosis.