Ayat ul Kursi (آیت الکُرسی) is in which Surah of the Holy Quran?

Ayat ul Kursi (آیت الکُرسی) is in which Surah of the Holy Quran?

A. Surah Al-ma’ida
B. Surah An-Nisa
C. Surah Al-Baqarah
D. Surah Al- A’raf