What is the most important part of the constitution to you and why?

This is more of an opinion question, but you might say the First Amendment is the most important to you. (Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.)

Explanation:

The First Amendment guarantees freedoms concerning religion, expression, assembly, and the right to petition.  It forbids Congress from both promoting one religion over others and also restricting an individual’s religious practices.  It guarantees freedom of expression by prohibiting Congress from restricting the press or the rights of individuals to speak freely.  It also guarantees the right of citizens to assemble peaceably and to petition their government.  

what are the options?

demand is the need and oportunity to buy a given good or service.