The correct answer is: B. Gandhinagar
The Adalaj Stepwell is a stepwell located in Adalaj village in Gandhinagar district of Gujarat, India. It was built in 1498 by Rana Veer Singh of the Vaghela dynasty for his wife Rani Rudabai. The stepwell is a fine example of Jain architecture and is one of the most popular tourist attractions in Gujarat.
Amreli is a district in Gujarat, India. It is located in the Saurashtra region of the state. The district headquarters is Amreli city. The district has a population of over 2 million people.
Banaskantha is a district in Gujarat, India. It is located in the northern part of the state. The district headquarters is Palanpur city. The district has a population of over 3 million people.
Bhavnagar is a district in Gujarat, India. It is located in the western part of the state. The district headquarters is Bhavnagar city. The district has a population of over 3 million people.
The Adalaj Stepwell is not located in any of the above districts. It is located in Gandhinagar district.