Which tool can be used to sniff probe requests from wireless clients, and pretends to be the access point the client is seeking?

Kismet is a passive wireless IDS and packet sniffer that monitors 802.11 traffic but does not respond to probe requests or impersonate access points in any way.

InSSIDer is a Wi-Fi scanner that visualizes nearby networks, channels, and signal strength for site survey purposes and has no rogue AP or active packet injection capabilities.

Aircrack-ng is a WEP/WPA/WPA2 key recovery suite focused on capturing and cracking authentication handshakes; it does not sniff probe requests or impersonate access points.

Karmetasploit is a Metasploit Framework automation script that implements the KARMA attack - it listens for broadcast probe requests in which wireless clients advertise previously associated SSIDs and then immediately spoofs those SSIDs so the client connects to the attacker-controlled AP. Once the victim associates, Karmetasploit can automatically deploy browser exploits, credential capture modules, and man-in-the-middle attacks against the connected client. This active probe-response impersonation is the defining behavior that distinguishes it from all other listed tools.