正解:C
The configuration provided in the OCR text shows the use of a route map named RM_LOCAL_PREF to set the local preference for BGP routes received from the neighbor 13.13.13.3. By setting a higher local preference, the BGP best path selection process will prefer routes with a higher local preference value.
Therefore, to force traffic to take the path R1-R3-R4, the local preference for routes received from R3 should be increased, making them more preferred than the current path via R2.