Which of the following phrases is a necessary condition indicator?

In logical reasoning, necessary condition indicators signal that a condition must be fulfilled for a certain outcome to occur. The phrase "except" serves as a necessary condition indicator because it implies that the condition it relates to is one that must be omitted or considered to define the limit of a broader scenario.

For instance, if we say, "Everyone except John passed the test," it indicates that John's presence is the critical exception; without that understanding, the statement about who passed the test would not hold true.

The other phrases do not function in this way: "nobody" suggests a universal negation, "all" indicates sufficiency by relating to each individual within a group, and "whenever" implies a sufficient condition, establishing a cause and effect relationship rather than a necessary requirement. Therefore, "except" is recognized as a necessary condition indicator because it specifies an essential component that must not be included for the larger statement to remain accurate.