To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Volume testing - This option is incorrect because volume testing is focused on testing the system's ability to handle large amounts of data, not specifically measuring the response to demand.
Option B) Stress testing - This option is incorrect because stress testing is focused on testing the system's ability to handle extreme workloads, not specifically measuring the response to demand.
Option C) Load testing - This option is correct because load testing specifically involves putting demand on a system by simulating real-world user loads and measuring its response. It helps evaluate the system's performance under expected loads and identify any performance bottlenecks.
Option D) Performance testing - This option is incorrect because performance testing is a broader term that encompasses various types of testing, including load testing. While it may involve measuring the system's response, it does not specifically refer to putting demand on a system.
The correct answer is C) Load testing. This option is correct because load testing involves putting demand on a system and measuring its response.