Choose or find odd pair of words - (Taiwan : Taipei) , (China : Mongolia) , (Iran : Tehran) , (Japan : Tokyo)

B. CHINA : MONGOLIA

Choose or find odd word - Foggy , Transparent , Turbid , Cloudy

B. TRANSPARENT

Choose or find odd letter group - CPRSV , CXHIA , MTOWF , RCFGL

C. MTOWF

Choose or find odd word - Garnet , Ruby , Graphite , Emerald , Topaz

C. GRAPHITE

Choose or find odd word - Discus , Spear , Javelin , Hockey

B. SPEAR