He contemplated a career as a medical doctor.

If you wanted to expand this sentence to include the following adverb clause, "before Dan joined the army," which would be the most effective expansion of this sentence?
Responses
A Before Dan joined the army, he contemplated a career as a medical doctor.Before Dan joined the army, he contemplated a career as a medical doctor.
B He contemplated a career as a medical doctor before Dan joined the army.He contemplated a career as a medical doctor before Dan joined the army.
C He contemplated before Dan joined the army a career as a medical doctor.He contemplated before Dan joined the army a career as a medical doctor.
D Before Dan joined he contemplated a career as a medical doctor the army.

A Before Dan joined the army, he contemplated a career as a medical doctor.