Concept:A trade association is a voluntary organisation of businesses in the same trade or industry that works for their common good.
Explanation:Trade associations are established and funded by member businesses.
Their main purpose is to look after the interests of those members.
They engage in advocacy, education, and networking on behalf of the industry.
A central function is to promote the general welfare of members.
This includes improving their business environment and offering support.
They do not build infrastructure for their members.
They do not pay member salaries.
They do not provide employment for members.
Hence, among the choices, the correct function of a trade association is to promote its members' welfare.
Answer:C. promote members' welfare