Final Answer:
A(n) "External" event occurs when something happens inside the system that triggers the need for processing. Option 3 is the answer.
Step-by-step explanation:
An external event in the context of system analysis and design refers to an occurrence or stimulus that originates from outside the system but impacts its operation. Option 3, "external," accurately describes events triggered by factors external to the system. Logical events (Option 1) involve conditions or states within the system itself. State events (Option 2) typically refer to changes in the internal conditions or status of the system.
Temporal events (Option 4) relate to time-based occurrences. In the given context, when an event occurs inside the system due to an external influence, it is appropriately termed as an "external" event.
Option 3 is the answer.