far 25.121 b) Takeoff; landing gear retracted. In the takeoff configuration existing at the point of the flight path at which the landing gear is fully retracted, and in the configuration used in §25.111 but without ground effect, the steady gradient of climb may not be less than 2.4 percent for two-engine airplanes, 2.7 percent for three-engine airplanes, and 3.0 percent for four-engine airplanes, at V2 and with --
you might want to read john's reply explaining why the 2,4% can vary. This is definitely not the correct answer.
The point at which the performance must be demonstrated is emphasised
No the configuration in which the performance must be demonstrated is emphasised.