Which instrument does not reflect bank angle, but shows rate of turn?

The Turn Coordinator is the instrument that indicates the rate of turn, not the bank angle. It provides pilots with a visual representation of how quickly the aircraft is turning. While the Turn Coordinator has a miniature airplane symbol that can help to indicate the level of bank, its primary function is to show the rate of turn in degrees per second. This allows pilots to maintain a standard rate of turn, which is typically 3 degrees per second.

In contrast, the Attitude Indicator directly reflects the aircraft's orientation relative to the horizon, showing both bank angle and pitch. The Heading Indicator displays the aircraft's magnetic heading but does not provide information about turn rates or bank angles. The Vertical Speed Indicator measures the rate of climb or descent, and it does not relate to turn dynamics at all.

Thus, the Turn Coordinator uniquely fulfills the role of indicating the rate of turn, making it the correct answer to the question.