Which of the following hormones is called as stress

Select the option that is related to the third letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster.

According to the logic used in the first pair, replace the question mark with the appropriate option given to

Cytology : Cells :: Entomology : ??

Select the related number from the given alternatives:

8 : ? :: 7 : 344

63 :  45 : : 85 : ?

In the following question, select the related word pair from the given alternatives. 

Hunger: Satiety

Select the combination of the letters that when placed sequentially in the blanks of the given letter series will complete the series.

Select a suitable figure from the answer figures that would replace the question mark (?) from question figure.

If 25 @ 20 = 5 and 28 @ 23 = 14, then 26 @ 21 = ?'. What will come in place of question mark?