There are two types of safety alerts in the ATC system. Which two are they?

• A. Terrain/Obstruction Alert (Low Altitude Alert); Aircraft Conflict/Mode C Intruder Alert (Traffic Alert)
• B. Terrain/Obstruction Alert (Low Alt. Alert); Aircraft Conflict/Mode C Intruder Alert (Traffic Alert)
• C. Terrain Alarm; Traffic Alert
• D. Low Alt. Alert; Aircraft Conflict

Answer: (B)

The safety alerts in ATC are two distinct warning kinds: terrain/obstruction alerts and traffic alerts. A terrain/obstruction alert warns when the aircraft is too close to the ground or obstacles, essentially signaling a low-altitude risk near terrain or structures. A traffic alert warns of potential conflicts with other aircraft, including situations where a nearby aircraft with a Mode C transponder could intrude into the same airspace, which is labeled as a traffic alert. The correct pairing reflects these two categories: Terrain/Obstruction Alert (Low Altitude Alert) and Aircraft Conflict/Mode C Intruder Alert (Traffic Alert). The other options either use incomplete terminology or omit one of the two alert types, so they don’t match the standard ATC safety-alert taxonomy.