What are the three key elements involved in Dead Reckoning?

The correct answer focuses on the essential components of Dead Reckoning, which is a navigation technique used to estimate one's current position based on a known starting point, the distance traveled, and the direction of travel.

In Dead Reckoning, establishing a known starting point is crucial because it serves as the reference from which all subsequent movements are calculated. The known distance allows a navigator to determine how far they've traveled from that starting point, while the known azimuth provides the direction of travel. Together, these elements help in calculating the estimated position accurately.

The other choices incorporate aspects that are less directly related to the established definition and methodology of Dead Reckoning. For instance, while terrain features and altitude may influence navigation, they are not fundamental components of the Dead Reckoning process itself, which is primarily concerned with distance, direction, and a starting reference point.