A

Step 1: Understand the concepts of retentivity and coercivity.
Retentivity (or remanence) is the ability of a magnetic material to retain its magnetism after the external magnetic field is removed.
Coercivity is the resistance of a magnetic material to changes in magnetization, meaning how much external magnetic field is required to demagnetize it.
Step 2: For a material to be a good permanent magnet, it should have high retentivity so that it maintains the magnetization after the magnetizing field is removed.
Furthermore, it should have high coercivity so that it does not easily get demagnetized by external magnetic fields.
Step 3: Therefore, the best choice that describes the properties needed for permanent magnets is Option A: high retentivity, high coercivity.
Conclusion: Materials with high retentivity and high coercivity are ideal for making permanent magnets, as they can retain a strong magnetic field against external influences.