Assertion (A): Birds have hollow bones and stream lined bodies. Reasoning(R): Hollow bones are the only feature, which enable the birds to fly.
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not the correct explanation of A
c. A is true but R is false
d. A is false but R is true

it is A.

Explanation: because they are both about the birds bones and birds need to fly if they don't have bones they can not fly

true, i don't really know what you're asking but from the info you provided im guessing the answer is true.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.