Final answer:
Arthur Ashe turned professional in tennis in 1969, making option B, 1968, the closest answer provided.
Step-by-step explanation:
Arthur Ashe turned professional in the year 1969. However, this differed from the options listed (A) 1964, (B) 1968, (C) 1972, and (D) 1975. Given these choices, the closest to the actual year Ashe turned pro would be option B, 1968. Arthur Ashe had an illustrious tennis career and became the first African American player selected to the United States Davis Cup team and the only black man ever to win the singles title at Wimbledon, the US Open, and the Australian Open.