C. Commensalism
"An association between two organisms in which one benefits and the other derives neither benefit nor harm."
Answer:
Prokaryote
Explanation:
a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. Prokaryotes include the bacteria and cyanobacteria.
Amphibia is the class of vertebrates which is considered to be the first to develop lungs. This allowed amphibians to live successfully on land as terrestrial organisms. Ichthyostega was the first primitive amphibians with nostrils and lungs. Amphibians adopted themselves to live on land with developed lungs.
D. Myosin and actin do not fully detach, so the muscle cannot relax.