What is the difference between mahayana buddhism and theravada buddhism

Buddhism is a faith that was founded by Siddhartha Gautama (“the Buddha”) more than 2,500 years ago in India. With about 470 million followers, scholars consider Buddhism one of the major world religions.

Theravada  the more conservative of the two major traditions of Buddhism (the other being Mahayana), and a school of Hinayana Buddhism. It is practiced mainly in Sri Lanka, Burma (Myanmar), Thailand, Cambodia, and Laos.

 Mahayana  one of the two major traditions of Buddhism, now practiced in a variety of forms especially in China, Tibet, Japan, and Korea. The tradition emerged around the 1st century AD and is typically concerned with altruistically oriented spiritual practice as embodied in the ideal of the bodhisattva.

Explanation:

dirty, contaminated water

contaminated food,

chlostrophobic living spaces,

mice infestation,

etc,

i think the answer is   b.