What attribute defines how many lines are allowed per event?

The correct choice identifies the attribute that specifies the maximum number of lines allowed per event within Splunk. MAX_EVENTS is a crucial configuration parameter that helps manage how Splunk processes incoming data. By setting a limit on the number of lines that are classified together as a single event, administrators can effectively control the granularity of the data being ingested. This can be particularly important for performance optimization, as it allows for the efficient indexing and searching of events without overloading the system with excessively large events.

The other options, while they sound plausible, do not correspond to the actual attribute used in Splunk. EVENT_LIMIT could refer to limitations on the number of events in a broader sense but does not focus specifically on lines per event. LINE_COUNT is not a recognized attribute in the Splunk configuration and MAX_LINES does not exist in the context defined in the question. Hence, the choice of MAX_EVENTS as the correct answer is well-supported by its widely recognized role in event limit settings within Splunk.