Which fixes on the IAP Charts are identified as initial approach fixes?

The correct answer identifies initial approach fixes as those designated by the letters "IAF." These letters stand for Initial Approach Fix and are specifically used to indicate the point in a procedure where an aircraft transitions from the en-route phase into the approach phase of a flight plan.

This designation is crucial for pilots, as it provides a clear reference point for initiating the approach sequence, ensuring that they can align their approach with the required altitudes, speeds, and procedures necessary for a safe landing. The use of IAF on charts allows pilots to effectively navigate and prepare for the approach by marking this transition clearly.

Other designators mentioned, such as IAM, star markings, or "IA" designations, do not refer specifically to the initial approach fix context. Therefore, while they may be relevant in other flight operations or technical discussions, they do not provide the same direct reference to initial approach fixes that "IAF" does.