Red Fort Delhi is the famous architecture made under the reign of which Mughal Ruler?

Shah Jahan

The correct answer is Option 2- Shah Jahan

Red Fort Delhi is the famous architecture made under the reign of Emperor Shah Jahan.

Abdul Rehman Chughtai (1899–1975) was a descendant of Ustad Ahmed Lahori, the chief architect of Shahjahan. He was  also the designer of the Jama Masjid and Red Fort in Delhi  and Taj Mahal in Agra.