Final answer:
Juan's need to consume more Cola for the same caffeine rush is an example of tolerance, a condition requiring increased substance intake to feel previous effects. The correct answer is a) Tolerance.
Step-by-step explanation:
Juan finds that he must drink more and more Cola beverage to get the same caffeine-induced rush. This is an example of tolerance, which is when a person requires an increased amount of a substance to achieve effects previously experienced at lower doses. Tolerance is often associated with physiological dependence and can become dangerous as it might lead users to consume levels of a substance that could lead to overdose or death. In this context, the use of Cola beverage for its caffeine content could lead to health issues if consumption continues to increase.
On the other hand, drug craving refers to a condition often associated with psychological dependence, where there is a strong desire or compulsion to use a substance. This is separate from tolerance, which is more related to the body's physical adaptation to a substance. In the case of the student's question, tolerance is the correct answer, not craving. So, the correct answer is a) Tolerance.