Answer:
C. Growing large root systems is one way plants compete for water
Explanation:
Mutualism is not between a species, so B is wrong. It also benefits both species, so A is wrong.
Answer:
C. Growing large root systems is one way plants compete for water
Explanation:
In mutualism, both species involved are benefited. Then, both options A and B are incorrect.
The most important resources for plants are water, sunlight and soil minerals. Then, option D is incorrect.
