Which is the odd number-pair?

Find out the odd word/letters/number pair/number from the given alternatives.

Find the odd word from the following:

Direction:  Select the odd word from the given alternatives. 

Find which does not belong to the group? Circle, Square, Rectangle, Triangle, Octagon 

Three of the following four numbers pairs are alike in a certain way and one is different. Find the odd one out.

A set is given, (B2, A1, F6, H8), such that its elements share a common property. Which of the given options does NOT have this property?

'Wet' is related to 'torrential rain' in the same way as 'prick' is related to.