Abdur Razzaq was a diplomat who visited India as an ambassador from the Timurid Empire during the medieval period. His primary purpose in India was to engage in diplomatic missions and represent the interests of his home country. This diplomatic role distinguished him from other travelers listed.

Here's a brief explanation of the other travelers mentioned:

Al-Biruni: Al-Biruni was a Persian polymath who visited India during the medieval period. He was primarily a scholar, scientist, and historian, not a diplomat.

Ibn Battuta: Ibn Battuta was a Moroccan scholar and explorer who traveled extensively in the medieval world, including India. His travels were more exploratory in nature, and he was not a diplomat.

Francois Bernier: Francois Bernier was a French physician and traveler who visited India during the 17th century. His travels were more for exploration and studying the culture and society of India, and he was not a diplomat.

Abdur Razzaq was the diplomat among the listed travelers, and that's the reason for his inclusion in the category of diplomats who visited India during the medieval period.

So,the correct option is [3].