Timmy is learning about the war in which much of Europe will be reduced to rubble.

A) Timmy is learning about the war in which much of Europe will be reduced to rubble.
The war has already occurred. Will be.. is incorrect

B) Timmy learned about the war in which much of Europe had been reduced to rubble.
We do not have 2 events following one after the other. Had been... is incorrect.

C) Timmy had learned about the war in which much of Europe was reduced to rubble.
Was reduced.. is correct.
Had learned indicated Timmy learnt before the war occurred which is not possible.

D) Timmy has learned about the war in which much of Europe must have been reduced to rubble.
The war has already occurred so the consequences are known. Must have been.. is incorrect.

E) Timmy learned about the war in which much of Europe was reduced to rubble.
CORRECT.

there is no time difference in the time frame of two events , so i think E should be correct answer.

Rezinka wrote:Timmy is learning about the war in which much of Europe will be reduced to rubble.

A) Timmy is learning about the war in which much of Europe will be reduced to rubble.
The war has already occurred. Will be.. is incorrect

B) Timmy learned about the war in which much of Europe had been reduced to rubble.
We do not have 2 events following one after the other. Had been... is incorrect.

C) Timmy had learned about the war in which much of Europe was reduced to rubble.
Was reduced.. is correct.
Had learned indicated Timmy learnt before the war occurred which is not possible.

D) Timmy has learned about the war in which much of Europe must have been reduced to rubble.
The war has already occurred so the consequences are known. Must have been.. is incorrect.

E) Timmy learned about the war in which much of Europe was reduced to rubble.
CORRECT.

B is tricky because of course we DO have two events in chronological order -- first much of Europe was reduced to rubble, then Timmy learned about it. Time sequence is implied by "learn about", though; I would expect different verbs for two events happening at the same time, as in I heard about the press conference in progress. You could use "learn about" in a contemporaneous setting, but it would be a little unusual.

Jim: Could you please explain why "B" is incorrect? What tense should be used in a situation where we have 2 events & one occurred before the other?

Can anyone elaborate why B is incorrect

This sentence is confusing; we have two different events in chronological
order ("the reduction of europe" happened first before Timmy "learned" of it.
What makes this an exception to the rule - i.e why "had" is wrong?