(Radio) When using the SIP protocol, a local digitmap is used for matching.

Huawei digitmap syntax uses x to represent any single digit 0–9. To match a 7-digit number starting with 7727, the correct pattern is 7727xxx.

A adds an unrelated rule 7726. and uses . incorrectly as a wildcard; not recommended.

B uses 772. (invalid for the intended match) plus 7727xxx; the first part is improper.

C matches only the 4-digit string 7727.

D contains 7727xxx (correct) and an additional 7727 rule; although the extra rule is unnecessary, it does not prevent correct matching.