Answer
(a) A living blood cell cannot be observed in an electron microscope, so a compound light microscope should be used. (b) The surface details on a hair, which is not alive, a dissecting microscope might show some information, but a scanning electron microscope is really needed to see fine detail.
Work Step by Step
This question asks you to review the information on different types of microscope and select the one which is most useful for the kind of information asked in the question (living cell; surface detail).