Final answer:
The line "the close contriver of all harms" refers to supernatural intervention and applies to Hecate, the goddess of witchcraft in Shakespeare's 'Macbeth'.
Step-by-step explanation:
The phrase "the close contriver of all harms" from Act III Scene V of Macbeth directly references Hecate's role in the play as the goddess of witchcraft who orchestrates mischief and manipulates events. Hecate characterizes herself with these words, taking pride in being the mastermind behind the chaos that ensues throughout the play. Therefore, the correct answer is: b) Refers to supernatural intervention; applies to Hecate.