Describe one instance of dramatic irony in act ii of twelfth night

Shakespeare's comedy Twelfth Night follows the outline of Elizabethan comedy as it has the elements of mistaken identity, separated twins, and gender-crossing disguise. With these elements comes the dramatic irony that contributes to the comedic effect of the play.

One instance of dramatic irony in act II of Twelfth Night is when Cesario/Viola describes the person he/she loves to Orsino, and we know that she is actually describing Orsino himself. Another is when Malvolio finds the letter and thinks it is from Olivia, but we know it was written by Maria.

i think the answer is either c or d

im thinking d might make more sense though

sorry if im wrong