What does the best rate-of-climb speed (VY) give?

1. 1The greatest altitude gain in a given distance
2. 2The longest glide distance with a failed engine
3. 3The most altitude gain in a given time
4. 4The lowest stall speed with flaps extended

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 8: Flight Instruments — Airspeed Indicator Markings — Other Airspeed Limitations, page 212