My answer would have been E as well.bpgen wrote:Well.. Experts, would you like to pay little attention here? and provide us your thoughts!
I'm certainly not an expert, but my understanding of Past Perfect is that there are two uses:
1. Two ideas that happened in the past, at mutually exclusive points in the past. Which ever happened before the other is associated with 'had'. Example: They had never seen the CN Tower before they moved to Toronto.
2. Two ideas that happened in the past, with the first idea continuing throughout time until we meet the more recent second idea. The first idea is associated with 'had'. Example: By the time they left Toronto, they had visited the CN Tower three times.
In the question, Tarduno's group found the evidence AFTER the rocks were magnetized. I don't see how 'had' can be associated with the 2009 finding using Past Perfect structure.
To further strengthen this point, Past Perfect should only be used when the timeline of actions is unclear. We are told one action happened in 2009, the other 3.45 billion years ago. Past perfect is not needed.
bgpen, what is the source of this question? OG? Manhattan?