NEET 2020 Zoology question on Biomolecules

1. A.
   The proinsulin has an extra peptide called C-peptide.
2. B.
   The functional insulin has A and B chains linked together by hydrogen bonds.
3. C.
   Genetically engineered insulin is produced in $E.Coli$.
4. D.
   In man insulin is synthesised as a proinsulin

[NEET 2020]