In addition to the DME slant range, which two pieces of information can the EHSI display when selected using the NAV button?

The correct choice is based on understanding the functionality of the Electronic Horizontal Situation Indicator (EHSI) in relation to navigation data provided by Distance Measuring Equipment (DME). When the NAV button is used, the EHSI is designed to provide essential information that enhances situational awareness during flight.

In this case, the combination of Ground Speed (GS) and Time To Go (TTG) is significant. Ground Speed provides the rate at which the aircraft is moving over the ground, which is crucial for pilots to understand their speed in relation to the terrain and other geographical references. Time To Go is an estimate of the time remaining to reach a waypoint, which is vital for planning and execution of flight paths, particularly during approach or holding patterns.

Other options, while they may include pieces of data related to navigation, do not align as clearly with the primary functions of the EHSI when using DME information. Therefore, the provision of GS and TTG supports effective navigation by giving pilots real-time data to make informed decisions.