Answer:
b)eutrophication
Explanation:
have you ever seen a lake or body of water with a layer of green on top? That's eutrophication due to heavy amounts of growth nutrients (primarily from runoffs from agriculture) in water. Simple plants utilize those and grow very fast. As they grow, they take up the oxygen and make water oxygen poor. These produce deadzones cuz the water life basically suffocates to death due to less oxygen. Eventually plants will also die
Multi cellular organisms are composed of many cells whereas unicellular organisms are composed of single cell. Multicellularity is indeed a progressive attribute of evolution where cells form tissue which forms organ and then organ system and finally an organism. Both multi cellular and unicellular organisms has advantages and disadvantages of their own. One of the main disadvantage of multi cellular organisms is that due to such a complex composition and functioning they require a large amount of energy for their maintenance and survival. Different organs and system require a huge amount of energy when it comes to comparison with unicellular organisms. A large amount of energy is also wasted in all these life processes. Though multi cellular organisms can survive in a variety of environmental conditions but then also their survival is difficult than any unicellular organism.
The bad effect is that the pesticides could go into the air or other places that they shouldn't be. But this is a quicker way.