2275. Which one of these is the odd one out and what's the big deal about it? 座 筋 卒砲 鵬


座  ZA, suwa(ru) - sit, seat, theater, constellation

筋  KIN, suji - muscle, tendon, line, reason, plot

卒  SOTSU - soldier, private, end

砲  HOU - gun, cannon

鵬  HOU, ootori - Peng, a legendary Chinese bird

All take 大 (DAI, oo(kii) - big) in front to make a word, but only 筋 uses the "Oo" reading (oosuji); the others are all "Tai/Dai-":   

大座  DAIZA - throne

大筋  oosuji - outline, main point

大卒  DAISOTSU - college graduate

大砲  TAIHOU - cannon

大鵬  TAIHOU - Name of a Sumo Wrestler