Consider the following statements regarding achievements in mathematics during the Gupta dynasty: 1. The most important achievement during this time was the discovery of the decimal system of notation. 2. The book Aryabhattiyam deals with Arithmetic, Geometry and Algebra. 3. Trigonometry was not known during this period. Which of the statements given above are correct?

• A. 1 and 2 only
• B. 2 and 3 only
• C. 1 and 3 only
• D. 1, 2 and 3