Question

a secondary sector
b quaternary sector
c tertiary sector
d primary sector

Explanation:

The tertiary sector involves providing services (like healthcare, personal services, retail). The images show a healthcare professional, a retail worker, and a service - related interaction, which align with tertiary sector activities. The primary sector is about raw materials, secondary about manufacturing, quaternary about knowledge - based services (less about direct service to consumers here). So the correct option is c.

Answer:

c. Tertiary Sector