Bellman ford algo has 2 targets. One , to report the existence of a negative Weight cycle reachable from source , 2nd , to find a well defined shortest path between two given vertices. So if -ve cycle present, in that case algo with return that -ve cycle exists , else it will return SPath from source
In this Qtn, reachability is a very imp point to choose correct option. Pls Look at gate 2009 bellman ford Qtn.