How do you know when something is being used as a symbol?

Select the correct text in the passage. which set of lines spoken by sebastian in act v, scene i, of twelfth night implies that olivia is not attracted to him simply because she is crazy? sebastian: this is the air; that is the glorious sun; this pearl she gave me, i do feel't and see't: and though 'tis wonder that enwraps me thus, yet 'tis not madness. where's antonio, then? i could not find him at the elephant; yet there he was; and there i found this credit, that he did range the town to seek me out. his counsel now might do me golden service; for though my soul disputes well with my sense, that this may be some error, but no madness, yet doth this accident and flood of fortune so far exceed all instance, all discourse, that i am ready to distrust mine eyes and wrangle with my reason, that persuades me to any other trust but that i am mad, or else the lady's mad; yet if 'twere so, she could not sway her house, command her followers, take and give back affairs and their despatch with such a smooth, discreet, and stable bearing, as i perceive she does: there's something in't that is deceivable. but here comes the lady.

No man thinks more highly than i do of the patriotism, as well as abilities, of the very worthy gentlemen who have just addressed the house. what appeal does he primarily use here

Nthis poem by ruskin bond, what does the use of the word heart-beats suggest about the narrator's attitude toward life?