Final answer:
A software developer works in the tertiary sector of an economy, which focuses on providing services. The quaternary sector, often seen as a subset of the tertiary sector, involves knowledge-based services and may also encompass roles like software development.
Step-by-step explanation:
The correct answer to the question is c) Tertiary. A software developer would be working in the tertiary sector of an economy. The tertiary sector is focused on providing services rather than the production of goods. Software development is a service that includes the creation, design, management, and maintenance of software.
Oftentimes people consider the work of software developers as part of the quaternary sector as well, which includes services such as information technology and knowledge-based services. However, the quaternary sector is typically a subset of the tertiary sector and focuses specifically on intellectual activities and knowledge-oriented services. This can include areas such as research and development, business consulting, and information sharing. In a broader sense, software development falls under the umbrella of the tertiary sector, but could also be classified within the quaternary sector depending on the specific nature of the job.