The amount of medicine because the different weights.
To ensure proper protection for food during storage the bottom shelf should be at least 3 inches - 3 feet above the ground. This is to protect the food from pests and other organisms that may cause disease and health-problems to people who are going to consume such produce. It is a common practice done in the past and have evolved in the process of manufacturing these days.
The answer is A because drug tolerance makes it so you have to take more and more drugs to get the effect you want. Meaning you are more likely to do too much to get your high and overdose.
