Choose the odd pair group in the following options?

Select the odd words from the given alternatives.

Find the odd number

An ‘Island’ is related to ‘Sea’ in the same way as an ‘Oasis’ is related to ‘_____’.

Select the related letter/ word/ number/ figure from the given alternatives.
FEAR : ui :: BORN : ?

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

GOOD : HSXT :: BEST : CIBJ :: COOL : ?

Select the related word/letters/number from the given alternatives.

25: 260 : : 30 : ?

Directions : In each of the following questions, select the related word from the given alternatives. 

Laugh : Joke : : ? : Cracker