From wikipedia:
"While the R-3S was being introduced in 1961, work started on a semi-active radar homing (SARH) version for high-altitude use, the K-13R (R-3R or Object 320) with 8 km range, [...] This version was designated AA-2B by NATO."
"[...]K-13M (R-13M, Object 380) for the IRH and K-13R (R-3R) for the SARH variant [...]These were dubbed Advanced Atoll (AA-2C and AA-2D, respectively)"
So I am unsure about whether the R-3R is AA-2B or AA-2D or what is going on here:D