With reference to the scientific progress of ancient India, which of the statements given below are correct. 1. Different kinds of specialised surgical instruments were in common use by ad first century. 2. Transplant of internal organs in the human body had begun by the beginning of ad third century. 3. The concept of sine of an angle was known in ad fifth century. 4. The concept of cyclic quadrilaterals was known in ad seventh century. Select the correct answer using the codes given below: [CSE (Pre) 2012]