95% of the cytoplasm of red blood cells is the___________?

Explanation

Haemoglobin makes up most of the dry protein content of a red blood cell and occupies much of its cytoplasm, allowing the cell to transport oxygen. Antibodies and enzymes are present in much smaller amounts and are not the main cytoplasmic component. Students may choose proteins because haemoglobin is a protein, but the question asks for the specific protein that predominates, namely haemoglobin.