The correct answer is D) promotes spiritual growth.
Prayer is effective in the physical world in that it promotes spiritual growth.
To pray is an act of faith. It is a way to communicate with good, show appreciation for all his favors and ask for help. It is a very personal moment and there are no rules for praying. Every religion has its own forms of praying according to its beliefs and teachings. But the essence is the same: a true and intimate connection with the Lord.