Choose the wrong A. Inertial mass is a measure of difficulty of accelerating a body by an external force whereas the gravitational mass is relevant in determining the gravitational force on it by an external mass.

B. That the gravitational mass and inertial mass are equal is an experimental result.

C. That the acceleration due to gravity on earth is the same for all bodies is due to the equality of gravitational mass and inertial mass.

D. Gravitational mass of a particle like proton can depend on the presence of neighbouring heavy objects but the inertial mass cannot.

Inertial mass:

The mass of an object A can be defined as the mass of the object obtained by measuring their accelerations under equal forces taking mass of B to be 1kg. This is known as inertial mass.

Gravitational mass:

The gravitational force exerted by a massive body on an object is proportional to the mass of the object. If F_A and F_B are the forces of attraction on the two objects due to the earth

and

Thus

If B is a standard unit mass, by measuring gravitational Force we can obtain the mass of object A which is known as gravitational mass.

By several experiments, it has been concluded that the inertial and gravitational mass are identical.

Therefore, gravitational mass of proton is equal to its inertial mass and is independent of the presence of neighbouring objects.