Which of these is a correct use of parallel structure?
A.our company will remove dead branches,cut down unwanted trees,and you can pay extra for us to clean up the mess.
B.we have to cut back these trees because they block the light,drop leaves in the gutters,and look like they’re dying
C.one worker climbs the tree,the other holds the ropes,and a stump grinding machine on the ground below
D.someone who cuts down trees has to be good at planning,climbing,and have good balance