The mother tongue of the Mughals was:

Turkish

The correct answer is Option (1) → Turkish

The Mughals, who were of Central Asian Turkic origin, initially spoke Turkish as their mother tongue. The founder of the Mughal Empire, Babur, wrote his autobiography "Baburnama" in Chagatai Turkish. Over time, however, as the Mughal Empire established itself in the Indian subcontinent, there was a cultural and linguistic shift. While Turkish remained in use, Persian became the predominant language of the Mughal court and administration. Persian was the language of literature, administration, and culture during much of the Mughal period. It was widely used by the Mughal rulers and elite, and many official documents, court proceedings, and historical works were composed in Persian. This shift to Persian as the court language was part of a broader trend of Persianate culture in the region during that period. So, while Turkish was the original mother tongue, Persian became the more significant language during the Mughal rule in India.

So, the correct option is [1].