Final answer:
Lester likely requested jersey number 56, which is against the NBA's rules because numbers with digits 6, 7, 8, or 9 cannot be easily signaled by referees with one hand.
Step-by-step explanation:
The NBA has specific rules regarding the jersey numbers that players can choose. According to these rules, players are allowed to wear numbers 0-99, but there are some restrictions on digits when it comes to the referee's ability to signal fouls using their hands. Given the options provided, the number that is against the NBA's numbering system is likely 56.
In the NBA, jersey numbers typically must be able to be signaled with one hand because each hand has only five fingers. Therefore, numbers such as 6, 7, 8, and 9 or any combination with these digits (like 56) are not usually allowed as they cannot be easily signaled by referees. Numbers like 23, 45, and 12 are commonly seen and are within the NBA's regulations.