Option 1 -> Ms. Sarojini Naidu was a prominent freedom fighter and poet known as the "Nightingale of India," but she was not involved in flag design.
Option 2 -> Ms. Bhikaji Kama unfurled an early version of the Indian flag in 1907 in Germany, but did not design the final national flag.
Option 3 -> Dr. Rajendra Prasad was the first President of India and played administrative roles, but was not the flag designer.
Option 4 -> Mr. Pingali Venkayya was an agriculturist and freedom fighter who designed the Indian National Flag with its specific design, khadi fabric, and exact color shades (saffron, white, green, and navy blue Ashoka Chakra).
Hence, Option 4: Mr. Pingali Venkayya -> He is credited as the designer of the Indian National Flag, having worked on various designs before finalizing the tricolor with the Ashoka Chakra that was adopted on July 22, 1947. He specified the fabric (khadi) and the precise color shades used in the flag. -> correct