The functional group of carboxylic acid is:
(a) Write the formula of the functional group present in carboxylic acids. (b) Name the functional group present in CH3−C≡CH. (c) Name the functional groups present in the following compounds : (i) CH3−CHO (ii) CH3−CH2−COOH (iii) CH3−O||C−CH3 (iv) CH3−CH2−CH2−OH