The correct option is B Observe continence.
Mahavira was the 24th Tirthankara of Jainism. There are basically five vows in Jainism. The first four vows- Satya, Ahimsa, Asteya (non-stealing) and Aparigraha (non-possession) were added by the 23rd Tirthankara Pasharvanath whereas the fifth vow continence, chastity or patience was laid down by Mahavira.