Correct Answer  Option 2 : 0.83
CONCEPT:

Mechanical advantage: It is a form of calculation that measures the amplified force taken by the mechanical system.
 It gives the ratio between the force applied to the load and the force needed to overcome the given force.
 It is a unitless expression since the two ratio quantities are the force.
 Mechanical advantage is also defined as the force created by the machine to the for applied on it.
The formula of mechanical advantage is given as:
MA = Load/Force = L/F
EXPLANATION:
Given, that F = 60 N, L = kg
Also, Force is given by,
Force = Load + Friction
F = L + f
f = F  L = 60  50 = 10
And,
MA = 50/60 = 0.83
So, the correct option is 0.83.