The Presence of a Mercurian Magnetic Field Surprised the Planetary

Multiple Choice

The presence of a Mercurian magnetic field surprised the planetary scientists on the Mariner10 team because:

A) Mercury is low in iron.
B) Mercury spins too rapidly to produce a stable dynamo.
C) It's still too hot for its core to have differentiated.
D) The dynamo theory predicted that Mercury was spinning too slowly for one.
E) Mercury lacks an iron core.