Final answer:
The attitude indicator, also known as the artificial horizon, provides an instantaneous, direct indication of the airplane's pitch and bank attitude.
Step-by-step explanation:
The only instrument that provides an instantaneous, direct indication of the airplane's pitch and bank attitude is the attitude indicator or artificial horizon.
This instrument is located on the cockpit's instrument panel and consists of a miniature aircraft that moves in response to changes in the plane's attitude.
By observing the position of the miniature aircraft relative to the horizon line on the instrument, the pilot can quickly determine the airplane's pitch and bank.