Explanation:

Trade guilds consisted of people from the Vaishya caste only: This statement is incorrect. Trade guilds in the early medieval period were not restricted to people from a specific caste. They were associations of merchants, artisans, and traders who came together for mutual benefit, irrespective of their caste. These guilds were more based on the economic activities and professions.

In the course of time, older shrenis emerged as sub-castes: This statement is incorrect. Shrenis were ancient guilds or associations, and their evolution into sub-castes is not a widely recognized historical development. The concept of sub-castes is more associated with the Varna system in ancient India rather than with the shrenis or guilds.