I think the correct answer would be option A. The work of Charles Kuen Kao is likely to have been most influenced by the work of Christian Doppler. Charles Kuen Kao was known is known as the Father of Fiber Optics. He pioneered the use of fiber optics in telecommunication which makes use of the transmission of light in fibers for communication. Doppler, on the other hand, was known for the doppler effect which is focused in the properties of waves like light waves. Charles Kuen Kao must have been studying this concept by Doppler to be able to establish his own invention.