Answer: Option 'A' is correct.
Step-by-step explanation:
Microplastic can be ingested by the corals and can smother the reefs.
It is the most likely impact of plastic and marine debris on coral ecosystems.
As the people is continuously throwing plastics in the river .
At last it goes into the ocean where coral reefs eat them which kill them.
Marine debris is also causing coral reefs killed like vessels which get lost damaged the coral reef.
Debris may contained net which can break off pieces of coral that get tapped in it.
Hence , option 'A' is correct.