Question 1An interface abstracts a module. Abstraction helps most in reducing the complexity of:1 pointdesigning the system.building the system.maintaining the system.cost and time estimates for developing the system.understanding the system.

The correct answer is "maintaining the system."

Here's why:

1. Designing the system: While abstraction can help in designing the system by providing a clear and simplified view of the system, it is not the primary benefit.

2. Building the system: Abstraction can also aid in building the system by hiding the complexity of the underlying implementation. However, this is not the main advantage.

3. Maintaining the system: This is where abstraction helps the most. By hiding the complexity of the underlying implementation, abstraction makes it easier to modify and maintain the system without affecting other parts of the system. This is the primary benefit of abstraction.

4. Cost and time estimates for developing the system: While abstraction can help in providing more accurate cost and time estimates by simplifying the system, this is not the main advantage.

5. Understanding the system: Abstraction can certainly aid in understanding the system by providing a simplified view. However, this is not the primary benefit.

So, the answer is "maintaining the system."