Once macbeth agrees to murder the king, he and lady macbeth plan that:

Lady Macbeth will make sure the guards are drugged allowing Macbeth to sneak in and stab the king to death

the correct answer is:

this is an example of the writer telling through description rather than showing through dialogue.

sometimes writers like to explain explicitely what's happening instead of adding dialogues of the situations., which is the case in this passage,

you do this because a real teammate puts the team first