The two most widely used hallucinogens are lsd and mescaline. mdma and marijuana. nicotine and caffeine. alcohol and marijuana. marijuana and lsd.

The correct answer is alcohol and marijuana.

The first and fourth answers are not true at all, as lsd is not one of the most widely used hallucinogens, very few people do it.

mdma is ecstasy, which is also not a widely used hallucinogen.

While nicotine and caffeine seems to be a good answer, it is still incorrect as caffeine kind of just gives you a spring, it is not a hallucinogen.

So, the correct answer is alcohol and marijuana because they both impact how we believe things occur when under their influence. And, when you think of most widely used, especially illegally among teenagers, it is these two.

i think your answer is c. measurement system in which the medication dosage was calculated.

i believe the answer would be 'd'.

hope this !