How Did Kenneth Lohmann Study the Navigation Ability of Young

How did Kenneth Lohmann study the navigation ability of young loggerhead sea turtles?

A) He placed radio transmitters on the shells of numerous hatchlings and tracked their migration patterns in the Atlantic ocean.
B) He genetically engineered turtles so they lacked magnetoreceptors and then studied their behavior compared to a control group.
C) He subjected turtles to an electromagnetic field opposite that of Earth's magnetic field, and then tracked the direction the hatchlings swam.
D) The loggerhead turtles were injected with magnetite to see what impact it had on their navigation.
E) Small magnets were glued to the hatchlings' shells, and their behaviors were monitored.