Materials suitable for permanent magnets must have which of the following properties?

What is the nature of the magnetic susceptibility of a diamagnetic substance?

For a paramagnetic substance, the magnetic susceptibility is

$A$ sample of paramagnetic salt contains $2.0 \times 10^{24}$ atomic dipoles each of dipole moment $1.5 \times 10^{-23} \; J \, T^{-1}$. The sample is placed under a homogeneous magnetic field of $0.64 \; T$ and cooled to a temperature of $4.2 \; K$. The degree of magnetic saturation achieved is $15 \%$. What is the total dipole moment of the sample for a magnetic field of $0.98 \; T$ and a temperature of $2.8 \; K$? (Assume Curie's law)

Curie temperature is the temperature above which:

Consider the following two statements $A$ and $B$ and identify the correct choice in the given answers.
$A$. Paramagnetism is explained by domain theory.
$B$. Susceptibility of a diamagnetic substance is independent of temperature.