Choose or find odd word - Oyster , Whelk , Scallop , Mussel , Clam

C. SCALLOP

In following number series, two terms have been put within brackets. Choose the appropriate option - 2,6,12,20,30,42,56,x

D. 72

Complete analogous pair - Ottawa : Canada : : Canberra : ?

D. AUSTRALIA

Choose analogous pair - Threat : Insecurity

A. CHALLENGE : FIGHT

Complete analogous pair - Tanning : Leather : : Pyrotechnics : ?

B. FIREWORKS