Question

each followed an essentially different current of ideas. source: the moon - voyage in the sentence above, current has the same or almost the same meaning as: controversy displacement measurement progression

Explanation:

In the given sentence, "current of ideas" implies a flow or progression of thoughts. "Progression" means a forward movement or development, which is closest in meaning to "current" in this context. "Controversy" refers to a dispute, "displacement" to a shift in position, and "measurement" to a quantification, none of which fit the meaning as well as "progression".

Answer:

D. progression