A is the answer
hope it helps
8H2. The actual equation doesn't make sense for 8H2. This is because in compounds it always says the number of atoms after the element symbol, but in this case, there is an 8 before it. This means that it isn't a compound.
Potassium, carbon, sulfur, hydrogen, oxygen, nitrogen, calcium, magnesium, sodium, phosphorus, iron, zinc, silicon, fluorine, boron, cobalt, manganese, chromium, and some others
Answer: "symbiosis" ; or, a "symbiotic relationship" .
_____________________________________________________________