Answer:
d. Is indicated when a magnetometer measures intervals of magnetism that are weaker than expected
Step-by-step explanation:
Magnetic field intensity is measured with a magnetometer on the surface of the Earth. Areas in which the magnetic field strength is lower or more than average are known as areas with magnetic anomalies, which may be due to the presence of rocks that have a different magnetic characteristics
Where the magnetic anomaly is negative, it is indicative of a magnetic field strength reading that is lower than average magnetic field which is generally obtainable
Therefore, the correct option is indicated when a magnetometer measures intervals of magnetism that are weaker than expected