Final answer:
4) Iago is the character in Shakespeare's Othello who declares he will wear his heart on his sleeve, which metaphorically suggests his deceitful intentions.
Step-by-step explanation:
The character who says he will wear his heart on his sleeve is 4)) Iago.
This phrase is found in William Shakespeare's play Othello, where Iago, the play's antagonist, uses this metaphor to declare his deceitful nature.
He makes this statement to show that he will pretend to display his emotions openly, only to manipulate others to his advantage.