“It is at the root of many other problems” means that

Directions: Read the following passage and answer the given questions.

One of the most serious problems confronting our country is that of a fast-growing population. In fact, it is at the root of many other problems. At the moment, thanks to planning, we are able to produce food and cloth sufficient for our people and even in some excess. But if the population continues to grow at this rate; it will not be long before the surplus turns into a bare minimum and even a deficit. The position in regard to accommodation is even now far from satisfactory in spite of our efforts.