D. Estuaries
Estuaries are a place where fresh and salt water mix.
They are found in bacteria and eukaryotes is false
The correct answer is:
A. Photosynthetic pigments absorb energy from light.

Paratism is the practice of living as a parasite in or on another organism. Mutualism is the way two organisms of different species exist in which each individual benefits from the activity of the other.
If i'm not mistaken amino acids can be used in our body to fuel a process in which cell replication occurs and DNA is made. So to use amino acids as fuel you would have to make sure everything is in correct order and lines up correctly from the time it's released from the nucleus to a ribosome.