Which one of the following is a valid reason for decomposing a process model into sub$-$process models?

$$ When the process model has $20$ activities

$$ When there are too many crossing sequence flows in the model that cannot be reduced by adjusting the layout of activities, events and gateways

$$ When two events of the same type cannot be linked by a sequence flow

$$ When there are too many different end events in a process model, and we wish to reduce the number of possible outcomes of the process