The correct option is
B Nucleated spindle shaped cells
Thrombocytes in frog are nucleated fusiform cells that are
considered to be functionally equal to mammalian
platelets. The mature thrombocyte cells are nucleated and are spindle shaped. Immature cells are spherical cells that
have a round nucleus and a more basophilic cytoplasm.
So, the correct answer is 'Nucleated spindle shaped cells'.