The activity described is passive wireless packet capture in monitor mode—specifically collecting management frames (such as beacon frames and probe responses) and observing client/AP interactions (including authentication-related frames) while not injecting or transmitting anything. In the Aircrack-ng suite, the tool designed for exactly this reconnaissance-and-capture purpose is Airodump-ng.
Airodump-ng is the component that listens on the air interface once the card is placed into monitor mode, then captures 802.11 frames and displays useful reconnaissance data such as BSSID, channel, encryption type, signal strength, and associated clients (stations). Critically, it can write captured traffic to files (e.g., .cap) for offline analysis—which matches the scenario’s “record into a capture file for later offline analysis.” This is a common CEH workflow: reconnaissance → capture → analyze, keeping the initial step non-intrusive.
By contrast:
Aireplay-ng (A) is primarily used for active attacks / packet injection (e.g., deauthentication, replay) and would typically involve transmitting frames.
Aircrack-ng (B) is used mainly for key cracking (WEP/WPA/WPA2 handshakes) after capture, not for passive collection itself.
Airbase-ng (C) focuses on creating a rogue AP / MITM-style setups, which is also an active transmission role.
So, for silent monitoring + capturing beacons/probes/auth frames to a file, the best match is D. Airodump-ng.
