In which of the following districts of U.P. is Aryabhatta Planetarium situated?

The correct answer is (a) Allahabad.

The Aryabhatta Planetarium is a planetarium in Allahabad, India. It was opened in 1986 and is named after the Indian mathematician and astronomer Aryabhata. The planetarium has a seating capacity of 300 people and offers a variety of shows on astronomy and space science. It also has a library and a museum.

The other options are incorrect because:

(b) Lucknow is the capital of Uttar Pradesh and is located in the central part of the state.
(c) Gorakhpur is a city in the eastern part of Uttar Pradesh.
(d) Rampur is a city in the western part of Uttar Pradesh.