NEET 2021 Biology question

With regard to insulin choose correct options. (a) C-peptide is not present in mature insulin. (b) The insulin produced by rDNA technology has C-peptide. (c) The pro-insulin has C-peptide (d) A-peptide and B-peptide of insulin are interconnected by disulphide bridges. Choose the correct answer from the options given below

• (A)(b) and (d) only
• (B)(b) and (c) only
• (C)(a), (c) and (d) onlyCorrect
• (D)(a) and (d) only