Refer to the exhibit. You want to set up an AS path filter that allows networks that originated from AS4, and autonomous systems that are directly attached to AS4, to enter R1. When you tested the filter, you noticed that something was wrong with it.
How can this be solved?
A. Change the regular expressing to ^4_0-9*$.
B. Change the regular expression to ^4_0-9+$.
C. Change the regular expression to ^4_0-9.*.
D. Change the regular expression to ^4_0-9.$.
Neither answer is correct. See https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13754-26.pdf