Correct Option: C

Chailakhyan (1936) a Russian investigator who researched on photoperiodism proposed the term ‘florigen’. According to him ‘Florigen Complex’, the true flowering hormone includes two group of substances formed in leaves (i) gibberellins which are necessary for the formation and growth of stem and (ii) anthesins which are necessary for flower formation. Acting together they form the substance named ‘florigen’.