Select the statements that are true considering the output of the command below:

$\backslash$table$[[$tcp$,0,0,0\mathrm{.}0\mathrm{.}0\mathrm{.}0$:$22,0\mathrm{.}0\mathrm{.}0\mathrm{.}0$:$***,$LISTEN$],[$tcp$,0,0127\mathrm{.}0\mathrm{.}0\mathrm{.}53$:$53,0\mathrm{.}0\mathrm{.}0\mathrm{.}0$:$**,$LISTEN$],[$tcp$,0,0,127*0\mathrm{.}0\mathrm{.}1$:$631,0\mathrm{.}0\mathrm{.}0\mathrm{.}0$:$***,$LISTEN$],[cp6,0,0$:::$80,$: : :$,$LISTEN$],[$cp$6,0,0$:::$21,$: : :$,$LISTEN$],[$cp$6,0,0$:::$22,$:::${?}^{***},$LISTEN$],[$cp$6,0,0$::$1$:$631,$:::${?}^{**},$LISTEN$]]$

$$ a$.$ There is a SSH server running.

b$.$ The port $80$ accepts only IPv$6$ communications.

c$.$ The ports $21$ and $22$ shown are udp.

d$.$ The ports $21,22,$ and $80$ are in use.

e$.$ Apache is installed and listening on port $80.$