Question

question 13
what is the objective of a network reconnaissance attack?
disabling network systems or services
denying access to resources by legitimate users
discovery and mapping of systems
unauthorized manipulation of data

Explanation:

Network reconnaissance attack aims to gather information about a target network. Discovery and mapping of systems is about gathering such information. Disabling network systems or services is more of a destructive action (like in some attacks after reconnaissance). Denying access to resources by legitimate users is a Denial - of - Service (DoS) or Distributed Denial - of - Service (DDoS) attack objective. Unauthorized manipulation of data is related to data tampering attacks.

Answer:

Discovery and mapping of systems