Business events (triggers) initiate business activities, and the guidance defines three types: external, internal, and time-based. External events originate from outside the organisation or business system; internal events originate within the business system (often as a result of managerial decisions); and time-based events occur at predetermined times (e.g., periodic schedules).

In the scenario, “targets are not met” is an internal business event because it arises from performance management within the business system—targets and performance monitoring are internal management concerns, and the “trigger” is the organisation’s own recognition that performance is below expectation (an internally generated condition).

“On a quarterly basis when a report is automatically generated” is a time-based business event because it is explicitly scheduled (quarterly) and happens due to time passing rather than an external party’s action. Time-based events commonly drive periodic reporting and review cycles.

“When the supplier signs a contract” is an external business event because the supplier is outside the organisation’s business system; the triggering action (contract signing) is performed by an external party, even though it leads to internal administrative work such as updating supplier records.

So there are 1 internal, 1 time-based, and 1 external event: option C.