Select the most appropriate idiom to fill in the blank.

My manager forced me to resign from my job as a chef since I underwent a spine surgery. I was depressed and had lost all hope. Later my father motivated me to open my own café and showed me ways to be independent. After all it is true that one should not ____________. 

Correct option is C

The most appropriate idiom to fill in the blank is "cry over spilt milk." This idiom means to waste time being upset about something bad that has happened and cannot be changed. In this context, it implies that one should not dwell on past misfortunes but rather look forward and move on.
· Meanings of the given options:
· Grease the palm: To bribe someone.
· Blow one’s own trumpet: To boast or brag about one’s own achievements.
· Cry over spilt milk: To lament or be upset about something that has already happened and cannot be changed.
· Blow hot and cold: To be inconsistent or change one’s mind frequently.