In what part of the plant are substances transported to where they are needed? A. Roots

B. Stem

C. Leaves

B. Stem.

hope it helps

B. Stem

Explanation:

In the stem part of the plant are substances transported to where they are needed. So, the option (B) is the correct answer.

good one: produce hormones that plants grow.

bad one: the problem with organic matter is that while plant nutrients are needed for crop growth, they can also stimulate excessive growth of the wrong plants – mainly, algae.