The first unstable compound formed during C3 cycle is:
(a) 3-carboxy,2-keto, 1,6 bi phosphorobitol
(c) 2-carboxy,3-keto,1,5 biphosphorobitol
(b) 2-carboxy,3-keto,1,5-biphosphorobitol
(d) 3-carboxy,3-keto, 1,6-biphosphorobitol​