_________ was the capital of Magadha before the 4th century BCE.

The correct answer is Option 3- Rajagaha

Rajagaha, also known as Rajgir, was the capital of Magadha before the 4th century BCE. It is located in the present-day state of Bihar in India.

The other options are incorrect:

• Varanasi is located in the present-day state of Uttar Pradesh in India and was never the capital of Magadha.
• Pataliputra, also known as Patna, became the capital of Magadha in the 4th century BCE.
• Mathura is located in the present-day state of Uttar Pradesh in India and was never the capital of Magadha.

Rajagaha was a major center of trade and commerce in ancient India. It was also a religious center for Hindus and Buddhists. The Buddha is said to have preached in Rajagaha on many occasions. The city declined in importance after Pataliputra became the capital of Magadha in the 4th century BCE. However, it remains an important pilgrimage site for Hindus and Buddhists today.