Both Buddha and Mahavira lived at the same time.

The correct answer is: B. Contemporary

• Simultaneous means happening at the same time.
• Contemporary means existing or happening at the same time.
• Coincident means happening at the same time by chance.
• Synchronised means happening at the same time in a planned or coordinated way.

In this case, Buddha and Mahavira were both born in the 6th century BCE, so they were contemporaries.