A system has three components in series with reliabilities $0\mathrm{.}9,0\mathrm{.}7,$ and $0\mathrm{.}8.$ What is the system reliability?

$0\mathrm{.}315$

$0\mathrm{.}504$

$0\mathrm{.}800$

$0\mathrm{.}500$

$2\mathrm{.}400$