Final answer:
The statement about PARA is False. Proper time (Δto) is the invariant time interval measured by an observer at rest relative to the event being observed, and it is a specific concept in physics related to relativity. The correct answer is B. False.
Step-by-step explanation:
The statement "PARA is used to show time or the duration of an activity" is False. The concept referred to in the question appears to be a mix-up with the term 'proper time,' which is a term used in physics. Proper time, represented as Δto, is the time interval measured by an observer who is at rest relative to the event being observed.
In the context of physics, especially in the special theory of relativity, proper time is an important concept as it remains invariant for different observers, regardless of their state of motion. It is the actual duration of an event as measured by a clock that is present at the event. Consequently, it is not used generically to indicate the duration of any activity but has a specific meaning in the realm of physics where it is related to measurements of time intervals in inertial frames of reference. So, the correct answer is B. False.