There are different ways to approach maintenance such as by planning for it $($planned or preventive maintenance$)$ or by waiting for something to go wrong before servicing an item $($unplanned or reactive maintenance$).$ Match each scenario below with the type of maintenand strategy being pursued in the scenario.

Sensors were installed to monitor equipment so that they could monitor temperatures and carry out servicing when the temperature reached a certain level.

The air$-$conditioning equipment was serviced once a year, regardless of how it was functioning.

An office building's management did not want to repair equipment unnecessarily, so management decided to wait until equipment failed before servicing it$.$

They had planned to replace the floor tiles the following year, but the unexpected departure of the tenant provided Choose...

Choose...

Unplanned maintenance

Opportunistic maintenance

Condition$-$based maintenance

Time$-$based maintenance

Opportunistic maintenance a good time to repaint and retile the house.

Condition$-$based maintenance $-{?}^{}$