Final answer:
The First Amendment was added to the Bill of Rights to protect fundamental freedoms including freedom of speech, press, religion, assembly, and petitioning the government. It prevents Congress from establishing a national religion and ensures the free exercise thereof, alongside other critical individual liberties.
Step-by-step explanation:
The correct answer to the question regarding the reason behind adding the First Amendment as part of the Bill of Rights is option (a) To protect freedom of speech. The First Amendment served several purposes when it was added to the Bill of Rights. Primarily, it aimed to prevent Congress from establishing a national religion, often referred to as the Establishment Clause, and it also protected the free exercise of religion. In addition to religious freedom, the First Amendment guards other fundamental freedoms such as speech, press, the right to assemble peacefully, and the right to petition the government for a redress of grievances.
It is important to note that while the First Amendment protects these freedoms, the other amendments in the Bill of Rights address different concerns. For example, the Second and Third Amendments add protections regarding the formation of militias and the quartering of soldiers; the Fourth through Eighth Amendments concern rights related to legal proceedings and punishments; the Ninth Amendment asserts the existence of other rights not specifically articulated in the Bill of Rights; and the Tenth Amendment reserves powers to the states and the people that are not delegated to the federal government.