Explanation
This option blocks calls to 9005551234 for any caller that reaches the Caller System Transfer conversation, which is one of the ways that Cisco Unity Connection can transfer calls outside. The default Transfer Restriction Table is associated with the default System Call Handler class of service, which is used by the Caller System Transfer conversation. Blocking 900 on this table prevents toll fraud by restricting calls to any number that starts with 900, which are usually premium-rate numbers. References:
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/10x/security/guide/10xcucsecx/10xcuc
https://www.cisco.com/c/en/us/support/docs/unified-communications/unity-connection/119337-technote-c

These two options are the correct rules to configure in the Unity Connection restriction table to block all calls to international phone numbers and numbers that contain 10 digits and begin with 0. The rules use wildcard characters to match any number that meets the criteria. The ? character matches any single digit, while the X character matches any single digit except 0. Therefore, 0??? blocks any number that starts with 0 and has nine more digits, while 0XXXXXXXXX blocks any number that starts with 0 and has nine more digits that are not
0:The other options are incorrect. A.9! matches any number that starts with 9 and has one or more digits after it, which is not the requirement. D.9* matches any number that starts with 9, which is also not the requirement.
E:0-9* matches any number that starts with a digit from 0 to 9, which is too broad and would block valid numbers as well. References:
* https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/10x/administration/guide/10xcucsagx/1
* https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/10x/administration/guide/10xcucsagx/1