Referring to the exhibit, what could be preventing the R1 router from receiving any prefixes from the R2 BGP neighbor?

A.
The neighbor 192.168.31.2 next-hop-self command is missing on R2

B.
R1 is using the wrong remote AS number in its neighbor 192.168.31.1 remote-as configuration

C.
The no sync command is missing on R1

D.
The no sync command is missing on R2

E.
There is a BGP version mismatch between R1 and R2

F.
There is a TCP session establishment problem between R1 and R2