As a network engineer, you have been sent to ZoomCar Enterprises to have a routine check on

the network devices. In doing so$,$ you suddenly notice that there are still some old$-$generation

routers installed at certain points. You plan on replacing these old routers with the new

upgraded ones. At which life cycle phase can you remove an old device from the network?

a$.$ The requirement phase.

b$.$ The documentation and maintenance phase.

c$.$ The implementation phase.

d$.$ The development phase.

Clear my choice