The correct option is C Autoradiography
Tissue culture refers to the aseptic culture of cells/tissues/organs or their parts under in vitro conditions. Cellular fractionation techniques refer to the separation of all cellular organelles through the sequential homogenization, filtration and purification methods. The phase-contrast microscopy takes advantage ability of different cell parts to alter the light passing through them in a subtle way according to their respective density to distinguish different cellular components. Autoradiography includes labelling of biomolecules with radioactive material (radioactive thymine for DNA, radioactive uracil for RNA and radioactive S for proteins) followed by localizing these radioactively labelled molecules by applying photosensitive emulsion on the surface of prepared slides. Thus, the correct answer is option A.