Final answer:
Kudzu kills other plants by shading them and preventing them from receiving sunlight.
Step-by-step explanation:
Kudzu, an invasive plant species in the American South, has a significant impact on its surrounding plants. It kills other plants through heavy shading, which prevents them from receiving sunlight. As a result, the shaded plants are unable to carry out photosynthesis and eventually die. Therefore, option 2) It kills other plants by shading is the correct answer.