Which direction is denoted by 90 degrees in navigation?

In navigation, degrees are used to specify direction based on a circular compass where 0 degrees corresponds to North. As you move clockwise around the circle, each quarter turn represents a specific cardinal direction: 90 degrees corresponds to East, 180 degrees to South, and 270 degrees to West. Therefore, when referring to 90 degrees in navigation, it is understood to indicate the direction East, making the chosen answer correct. Understanding this angular representation is essential for navigating properly and for conducting flight operations safely and effectively.