Step 1: Tagore's Concept Explained.
Rabindranath Tagore's perspective on spirituality and humanism centered on: - "The Religion of Man," asserting that genuine religiosity resides in humanistic principles rather than prescribed rites. - His philosophy underscored the intrinsic unity of humanity, advocating for global peace and accord.
Step 2: Determination of Correct Answer. Designation of "The Religion of Man" as the accurate response, identified by the numeral 1.
Final Answer: \[ \boxed{\text{The correct answer is 1. The Religion of Man.}} \]