I need help on this question:

29. A common feature of thermal pollution and artificial eutrophication is that they both
a. have sources that are difficult to identify and control
b. cause large mats of algae to bloom in fresh water
c. are a result of power plants and other industrial activity
d. decrease the amount of oxygen dissolved in water

'...Eutrophication caused by humans is called artificial eutrophication. Fertilizer from farms, lawns, and gardens is the largest source of nutrients that cause artificial eutrophication. Phosphates in some laundry and dish washing detergents are another major cause of eutrophication. Phosphorus is a plant nutrient that can cause the excessive growth of algae. In bodies of water polluted by phosphorus, algae can form large floating mats, called algal blooms. As the algae die and decompose, most of the dissolved oxygen is used and fish and other organisms suffocate in the oxygen-depleted water.

...When the temperature of a body of water, such as a lake or stream increases, thermal pollution can result. thermal pollution can occur when power plants and other industries use water in their cooling systems and then discharge the warm water into a lake or river. thermal pollution can cause large fish kills if he discharged water is too warm for the fish to survive. But most thermal pollution is more subtle. If the temperature of a body of water rises even a few degrees, the amount of oxygen the water can hold decreases significantly. As oxygen level drop, aquatic organisms may suffocate and die. If the flow of warm water into a lake or stream is constant, it may cause the total disruption of an aquatic ecosystem.'

hold on, i think i got it. is it D?

sorry about that.

This is a repost from yesterday. I didn't get an answer to this.

Can someone please help me, please ?!
Thanks

Check this definition, reread the above paragraphs, and then tell us what you think.

http://dictionary.reference.com/browse/Eutrophication

The answer is D

Yes, you are correct! The correct answer is D. Thermal pollution and artificial eutrophication both result in a decrease in the amount of oxygen dissolved in water.

To arrive at this answer, it is important to understand the definitions of thermal pollution and artificial eutrophication.

Thermal pollution occurs when the temperature of a body of water increases due to the discharge of warm water from power plants or industries. This increase in temperature can lead to a decrease in the amount of oxygen that the water can hold, resulting in suffocation and death of aquatic organisms.

Artificial eutrophication, on the other hand, is caused by human activities such as the excessive use of fertilizers in farms, lawns, and gardens, or the presence of phosphates in laundry and dishwashing detergents. These nutrients promote the growth of algae in bodies of water, leading to the formation of large floating mats called algal blooms. As the algae die and decompose, the dissolved oxygen in the water is consumed, resulting in suffocation of fish and other organisms.

Both thermal pollution and artificial eutrophication have a detrimental effect on the oxygen levels in water, which can lead to the death of aquatic organisms. Therefore, option D, "decrease the amount of oxygen dissolved in water," is the correct answer.