Answer:
I'm the source of all emotion, but I'm caged in a white prison.
What must be looked through in order to see?
It is something you make after you've weighed your options.
I can be found in seconds, minutes and centuries, but not in days, years or decades.
What instrument plays from the heart?
What language does a billboard speak?
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?