GMAT Critical Reasoning (CR) | Re: A reason Larson cannot do the assignmen

I can See both B and E are contenders and Can't Eliminate both.
D is definitely wrong because it is saying ANY kind of scheduling conflict.
Tried using Negating technique Both B and E destroy the conclusion .
please need help regarding this question.
If the post solves my dilemma +kudos guarantee . thank you.

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