The Clo wants to host a hackathon to boost innovation. So far, sign$-$ups to participate have been low, She does not want to force people to participate, but she wants better attendance. You take a chance and recommend she announces that participation in the event is limited$,$ and signups will be open for only a short time. Which influencing principle are you recammending?

Scarcity

Social proof

Commitment and consistency

Authority