Explanation:
Magnetic susceptibility:
Magnetic susceptibility is a measure of the extent to which a material can be magnetized in the presence of an external magnetic field. It is defined as the ratio of the magnetization M of the material to the applied magnetic field strength H.

Diamagnetic substances:
Diamagnetic substances are those materials that are not attracted to a magnetic field. They have a negative value of magnetic susceptibility, which means that they tend to create a magnetic field in the opposite direction to the applied magnetic field. Diamagnetic substances have a weak response to the applied magnetic field and their magnetic susceptibility is generally temperature independent.

Paramagnetic substances:
Paramagnetic substances are those materials that are weakly attracted to a magnetic field. They have a positive value of magnetic susceptibility, which means that they tend to create a magnetic field in the same direction as the applied magnetic field. Paramagnetic substances have a stronger response to the applied magnetic field compared to diamagnetic substances.

Ferromagnetic substances:
Ferromagnetic substances are those materials that exhibit a strong attraction to a magnetic field. They have a very high positive value of magnetic susceptibility, which means that they tend to create a magnetic field in the same direction as the applied magnetic field. Ferromagnetic materials can retain a significant amount of magnetization even after the applied magnetic field is removed.

Water:
Water is a diamagnetic substance. It has a negative value of magnetic susceptibility, which means that it tends to create a magnetic field in the opposite direction to the applied magnetic field. Therefore, water is diamagnetic in nature.

Typical domain size of a ferromagnetic material:
The domain is a region within a ferromagnetic material where the magnetic moments of the atoms are aligned in the same direction. The typical domain size of a ferromagnetic material is much larger than 1 nm. It can range from a few micrometers to millimeters, depending on the material.

Conclusion:
The true statement among the given options is option B - The magnetic susceptibility of diamagnetic substances is temperature independent. Diamagnetic substances have a negative value of magnetic susceptibility and their response to the applied magnetic field is weak. Additionally, their magnetic susceptibility does not depend on temperature.