Option (a) is not correct: Nat Bhairavi is the Carnatic equivalent of the Asavari Thaat in Hindustani classical music, which resembles the natural minor scale.
Option (b) is not correct: Kamavardhini (also known as Pantuvarali) corresponds directly to the Purvi Thaat in Hindustani music, utilizing sharp and flat notes distinct from Bilawal.
Option (c) is not correct: Hanumatodi is the Carnatic counterpart to the Bhairavi Thaat of the Hindustani system, featuring four flat notes.
Option (d) is correct: Dheera Shankarabharanam is the 29th Melakarta raga in Carnatic music. It uses all natural notes (Suddha Swaras), making it structurally identical to Raga Bilawal, which is the foundational major scale (Suddha Thaat) of Hindustani music.
Source: https://www.newindianexpress.com/opinion/2026/Jan/25/faithline-shankarabharanams-grace
The Notification for the Civil Services Examination, 2021 was released by the Commission on March 04, 2021. The notification contains all the details related to the examination dates, number of vacancies, eligibility criteria, syllabus, application process, fee, exam centers etc. The exam is being conducted to fill in 712 vacancies as listed in the notification with 22 vacancies reserved for Persons with Benchmark Disability. The Preliminary examination will be held on October 10 2021. Candidates can visit the Commission’s website  to fill the application form. Detailed instructions for filling up online applications have been provided on the website. The application window was closed on March 24 2021. The admit cards for the Preliminary Examination were made available from September 16 2021. The admit cards can be downloaded from the Commission’s website on the above mentioned link.