Answer :

The question is asking to choose among the following choices the the ribosome of a cell is most responsible in what function, base on the following choices, the possible answer among them is in letter C. manufacture of protein. I hope you are satisfied with my answer and feel free to ask for more 
The correct option is C.
Ribosomes are part of the organelles that are found in the eukaryotic cells. Ribosomes are primarily responsible for the synthesis of proteins in living cells. Ribosomes produce the proteins according to the specifications of messenger RNA. The number of ribosomes that can be found in a cell depend on the level of activity of that cell. Ribosomes can be found freely suspended in the cytoplasm or attached to the endoplasmic reticulum.