How does the ocean floor preserve evidence of past magnetic reversals.

(A) The ocean floor is uniformly old, preserving the Earth's 4.6 billion history.

(B) Isotopic analysis of ocean core sediments help determine sea floor age and this can be used to infer past magnetism.

(C) Magnetic particles in basalt orient with the magnetic field in force at the Curie Point.

(D) Mantle hot spots are always oriented to the magnetic field.