Both Assertion A and Reason R are correct, and R is the correct explanation of A. About 20–25% of CO$_2$ is transported in the blood as carbaminohaemoglobin. The formation of carbaminohaemoglobin is favored by high pCO$_2$ and low pO$_2$, conditions that prevail in the tissues.
Given below are two statements:
Statement I: Transfer RNAs and ribosomal RNA do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.
In the light of the above statements, choose the most appropriate answer from the options given below: