Religious faith is vital to the following: a. Animals b. Human beings c. Heavenly bodies d. Gandharvas

The correct choice is human beings. According to the Hindu religion, religious faith is important to humanity. Religious faith provides information about the universe and all life forms. It also offers guidance and explains the interaction between man and the universe. Religious faith is important because it provides an opportunity for man to connect with divine beings.
Religious faith is viewed as man’s attempt to seek answers to some serious life questions.  Adherents of Hinduism observe diverse beliefs. However, there exist core beliefs that define the Hindu religion. These views form the common bond among followers of the faith. The belief system ascertains the existence of a Supreme Being.  It also explains the sacred nature of life. Hindus believe in Karma and reincarnation. These aspects explain how human beings should live and what to expect after death. Thus, the concepts of religious faith are mostly targeted to human beings.
The answer has been provided based on Hinduism because of choice D. Gandharvas. The option provided some context and direction for the answer.