The correct answer is letter C. Rock Cycle. Living organisms involved in carbon cycle, oxygen cycle, and in nitrogen cycle. These are involved in the air that living organisms are taking in and out.
Answer : The type of reaction described in the sentence is Synthesis or Combination
Explanation :
The balanced equation for the reaction between Phosphorous and Oxygen gas can be written as

From the above equation we can see that there are two different reactants ( P and O₂ ) which are combining with each other to give a single product.
This type of reaction is known as Combination or Synthesis.
A general form of Synthesis reaction is given below.

Here we can conclude that a synthesis / combination reaction is the one where 2 or more reactants combine together to give only one product .
Positive ions or molecules that have lost one or more electrons where negative ions are actually oxygen atoms with extra negatively charged electrons.