The Vishnupad Temple, an important Hindu pilgrimage site, is located in:

The correct answer is: a) Varanasi.

The Vishnupad Temple is a Hindu temple located in Varanasi, India. It is one of the most important pilgrimage sites in Hinduism, and is believed to be the footprint of Vishnu, one of the principal deities of Hinduism. The temple is a large complex with several shrines, and is a popular tourist destination.

The other options are incorrect because:

• Gaya is a city in the Indian state of Bihar. It is an important pilgrimage site for Hindus, as it is believed to be the place where the sage Vishwamitra performed a sacrifice to obtain a son.
• Patna is the capital of the Indian state of Bihar. It is an important cultural and educational center, and is home to several universities and museums.
• Munger is a city in the Indian state of Bihar. It is an important industrial center, and is home to several factories and mills.