C$)$ There are $2$ available actions:

Fly$($p$,$a$,$b$)$: Fly plane p from airport a to airport b$.$

Transfer$($c$,$p$,$a$,$b$)$: Transfer cargo $c$ using plane $p$ from airport a to airport b$.$

$\backslash$table$[[$Action$,$Fly$($p$,$a$,$b$),$Transfer$($c$,$p$,$a$,$b$)],[$Preconditions$,$At$($p$,$a$),$At$($p$,$a$)],[,,$At $($c$,$a$)],[$Effect$,$notAt$(p,a),$notAt$(c,a)$