Amongst the following, the total number of physical properties which are extensive are:
A- Density
B- Viscosity
C- Surface tension
D- Dipole moment
E- Volume
F- Refractive index
G- $\Delta G$
H- $\Delta H$
I- $\Delta U$
J- $\Delta S$

(A)- 5
(B)- 3
(C)- 4
(D)- 6

Hint: Extensive properties are those properties which depend on the amount of the substance present. If the amount of substance changes then the property also changes.

Complete step-by-step answer:
Let’s see what the answer is:
Density is defined as the ratio of mass of a substance to the volume occupied by the substance. It is an intensive property.
Viscosity is defined as the internal resistance offered by a liquid. It is the ratio of force to area. It is an intensive property.
Surface tension is defined as the property of a liquid to resist an external force. It is also the ratio of force to area. It is an intensive property.
Dipole moment is defined as the product of either change and the distance of separation between the charges. It is an intensive property.
Refractive index is defined as the ratio of speed of light in one medium to the speed of light in another medium. It is an intensive property.
Physical properties like mass, volume, enthalpy, entropy, energy, Gibbs free energy, etc. depend on the amount of substance present.
Therefore, volume, $\Delta G$, $\Delta H$, $\Delta U$ and $\Delta S$ are extensive properties.
Hence, the answer for the given question is option (A).

Additional information:
Intensive properties are those properties which are not dependent on the amount of the substance present in the system. For example: density, pressure, etc.

Note: The ratio of two extensive properties give an intensive property. Some properties like density may look extensive but actually they are a ratio of two extensive properties. So, the formula for the properties should be checked.