In the Vitthala temple, the principal deity was Vitthala, a form of Vishnu. It was worshipped in which region?

Maharashtra

The correct answer is Option 2 - Maharashtra

Vitthala, a form of Vishnu is generally worshipped in Maharashtra. 

Another shrine, the Vitthala temple, is also interesting. Here, the principal deity was Vitthala, a form of Vishnu generally worshipped in Maharashtra. The introduction of the worship of the deity in Karnataka is another indication of the ways in which the rulers of Vijayanagara drew on different traditions to create an imperial culture.

(Vitthala temple is in Hampi, Karnataka. However, Vitthala was a form of Vishnu generally worshipped in Maharashtra).