Question

Substance a is required for the synthesis hprmone b deficiency of b leads tp disturb metabolism and swelling on neck ,causing disease c identity a,b,c

Answer 1

Substance a is iodine which is required for the production of hormone b i.e. thyroid hormones  (T3 and T4) whose deficiency  causes goitre in which neck of the person swells up so c is goitre.