Correct Answer  Option 2 : 4600 N
The correct answer is 4600 N.
CONCEPT:

Rocket: A rocket works by expelling gases from one end at a very high velocity.
 The escaping gas has a very high speed and this with its mass translates to a very large momentum. due to the principle of conservation of momentum the body of the rocket is pushed forward.
 The propulsion of all rockets is explained by Newton's third law of motion.
 A rocket's acceleration depends on three major factors:
 Exhaust velocity
 Rate the exhaust is ejected
 Mass of the rocket
The amount of thrust (F_{t}) produced by the engine is given by:
F_{t }= v × \(\frac{dm}{dt}\)
Where v is the speed of exhaust gases with respect to rocket and \(\frac{dm}{dt}\) is fuel consumption rate or mass per unit time
The acceleration (a) of the rocket is given by:
a = F_{t}/M
Where M is the mass of the rocket and F_{t} is the thrust
CALCULATION:
Given that:
M = 850 kg, Fuel consumption rate = \(\frac{dm}{dt}\) = 2.3 kgs1
Speed of the exhaust gases relative to the rocket engine (v) = 2000 ms1
Thrust produced by the engine = Ft = v × \(\frac{dm}{dt}\) = 2000 × 2.3 = 4600 N