Which of the following routing technique(s) is/are used in distributed systems?
(A) Fixed Routing
(B) Virtual Routing
(C) Dynamic Routing

Explanation

Distributed systems use several routing strategies: fixed routing pre-computes one static route for each pair of nodes; virtual routing sets up a fixed logical path (a virtual circuit) for the duration of a session even though the underlying physical route may vary; and dynamic routing recomputes routes at run time based on current network or load conditions. All three are legitimate, well-established techniques used in distributed and computer networks, so none can be excluded. The correct answer is therefore all of (A), (B) and (C), option (iv).