A Denial of Service attack is intended to make a host, server, or network service unavailable to legitimate users. It usually works by exhausting system resources such as bandwidth, CPU, memory, connection tables, or buffers, so valid users cannot access the service normally. Therefore, statement B is correct because the essential purpose of a DoS attack is to interrupt services or block resource access on the target.

Statement C is also correct. Many DoS attacks attempt to consume queue space, session resources, or buffers on the target so that new connection requests cannot be processed. This is a common way of making a service unavailable. Statement A can also be correct in the context of some DoS methods, because attackers may use IP spoofing to hide their identity, bypass simple filtering, or increase the difficulty of tracing the attack source.

Statement D is incorrect because DoS attacks are designed to affect availability , not to create unrecoverable physical damage to hardware. They may crash systems, overload services, or interrupt access, but they do not normally destroy the target device physically.