Kobe Bryant played as number 24 before his retirement from the NBA. However, option (a) is also correct because young Kobe Bryant also played as number 8 in the NBA. Kobe Bryant started his career as NO.8 and ended his career as NO.24.
Kobe Bryant is the only player that successfully had two jersey number from the same team. According to ESPN.
He chose the number because of his Adidas camp number, which was 143, which add up to 8. When he played as NO.8, he won three NBA championship titles. He scored 16,777 points and appeared in eight all-star games.
He got two NBA championship titles, appeared ten times in the all-star game, and scored 16,886 points wearing NO.24.