Which of the following statements are true?
(a) Proteins are the heteropolymer of $$\alpha $$-amino acid.
(b) Sugar found in nucleic acid, is in the form of $$\beta $$-form.
(c) Nucleic acids show acidic nature.
(d) 5-methyl uracil binds with the first carbon atom of the ribose sugar.
(e) Collagen is the most abundant protein in the plant world.