Read the given paragraph with few blanks. __(i)__ body of birds reduces resistance offered by wind. Their __(ii)__ are modified into wings which help them in flight. Birds have __(iii)__ bones which make their body light. Birds are __(iv)__ and maintain constant body temperature. __(v)__ are attached to their lungs which serve as reservoirs of air. Birds maintain equilibrium in flight due to well developed __(vi)__ of brain.
Select the option that correctly fills any 3 of these blanks.
A(i) Spindle shaped, (ii) Hindlimbs, (vi) Cerebrum
B(ii) Forelimbs, (iv) Homeothermic, (vi) Cerebellum
C(i) Radially symmetrical, (iii) Pneumatic, (v) Air sacs
D(iv) Poikilothermic, (v) Air sacs, (vi) Cerebrum