What’s the best answer , a , b , c or d

The Basic Concept

When we look at an object at rest, we say that it is in equilibrium since all the forces being applied on it, cancel out

now, if one of the force was slightly more than the other one in the same case. The object will start to move and NOT be in equilibrium

BUT

if an object is in a vacuum and moving on a frictionless surface, the object will attain equilibrium after some seconds since it will be moving with constant speed and all the forces acting on it will be equal

Hence, if the object is accelerating. we can say with surety that the object is not is equilibrium since from the second law of motion,

F = ma ; when a is a non-zero value, there is definitely some net force being applied on the object

Looking at the given case

in the question, we are given that the object is 'accelerating'  upwards

we proved above that if an object is accelerating, there is some net force on that object and hence the object is NOT in equilibrium

Since the object is accelerating, from the second law of motion:

F = ma; m cannot be zero and if a is a non-zero value as given in the question, there is definitely some net force on the object

Since there is some force being applied on the object, the object is NOT in equilibrium

Conclusion

Since we found that the object is NOT in equilibrium and that there is some net force on the object,

The first option is correct

the answer is b ) square root of 5

you can cut your hand off if your not