To improve your probability of performing a learned skill well, or your probability of remembering something in a variety of circumstances, you should

A) avoid emotional arousal at the time of learning.
B) stay awake for as long as possible after learning.
C) study or practice under a variety of conditions.
D) study or practice under consistent, predictable conditions.

Studying or practicing under a variety of conditions helps to improve memory and performance in different contexts. This is known as the principle of encoding specificity, which suggests that the more closely the conditions at the time of learning match those at the time of retrieval, the greater the likelihood of successful recall. Varying the conditions in which you study or practice the skill helps to create more retrieval cues, making it easier to retrieve the information later on. Avoiding emotional arousal may be an important consideration for some types of learning, but it is not a general rule for improving memory and performance. Staying awake for as long as possible after learning is also not an effective strategy, as sleep is important for consolidating memories. Finally, practicing under consistent, predictable conditions may help to improve performance in specific contexts, but it does not enhance memory or transfer of learning to different situations.