Final answer:
A process with multiple threads of control a. can perform more than one task simultaneously, enhancing performance and efficiency.
Step-by-step explanation:
A process having multiple threads of control implies that it can do more than one task at a time. This means that the process can perform multiple operations concurrently, which can lead to increased efficiency and better utilization of system resources. Multithreading is a common feature in modern operating systems and applications, allowing them to execute tasks in parallel to achieve better performance. In contrast, the other options listed do not accurately describe a multithreaded process: it is not limited to doing only one task faster, does not have to use only one thread per process, and the question's assertions are not irrelevant.
Using multiple threads allows a process to handle various tasks simultaneously. For instance, in a web browser, one thread can display the user interface while another downloads data or plays a video, ensuring that the browser remains responsive even while performing the respective tasks.