The substance that fills the space between organelles in a cell is Cytosol. Cytosol, also known as cytoplasmic matrix, is a gel-like substance that makes up the majority of the cell's cytoplasm. It surrounds organelles within the cell and provides a medium for various cellular processes to occur.
Cytosol consists of water, salts, and organic molecules such as proteins, sugars, and amino acids. It acts as a solvent where metabolic reactions take place and helps in the transport of molecules within the cell.
Therefore, the correct answer to the question is:
B Cytosol
