The question asks to identify the author of the book 'Rihla', which details the social and cultural life of the Indian subcontinent during the fourteenth century.
The book 'Rihla' was authored by Ibn Battuta. He was a Moroccan scholar and explorer who traveled extensively throughout the Islamic world and beyond.
Ibn Battuta's travels in the fourteenth century, particularly his time in the Indian subcontinent, provided valuable insights into the era's society, culture, and politics. His work, 'Rihla' (meaning 'Journey'), is a primary source for historians studying this period.
Therefore, Ibn Battuta is the correct author associated with 'Rihla' and its description of 14th-century India.