Choose or find odd word - Hypothesis , Assumption , Observation , Experiment

D. EXPERIMENT

Choose or find odd word - House , Cottage , School , Palace , Hut

C. SCHOOL

Choose or find odd letter group - BD, IK, PN, SU, WY

C. PN

Choose or find odd word - Whale , Dolphin , Shark , Cod , Starfish

A. WHALE

Choose or find odd word - Copper, Tin, Brass, Platinum, Zinc

C. BRASS