Here is my answer. IMO the answer is
Recently, some astronomers spotted a gap in the extended outer atmosphere of the
Sun, a discovery suggesting that a gigantic number of particles escaped into space as geomagnetic storms that at times cause damage to the Earth’s satellites and power grids.
A. Sun, a discovery suggesting that a gigantic number of particles escaped
- This makes the best sense//
B. Sun, a discovery that suggested the escape of a gigantic amount of particles
- keeping suggested which is in the past does not bear well with the rest of the phrase which is still at the present (cause)
C. Sun suggesting that a gigantic number of particles escaped
- modified issue
D. Sun that suggests a gigantic number of particles that escaped
- that used twice. incorrect
E. Sun, a discovery suggesting a gigantic amount of particles escaping
- escaping means its happening now and ongoing, but it does not sync with the happening 'at times'. So escaped would be the right usage.
Day 21 Question of the Verbal Contest:
Race Against the GMAT Club TimerPlease make sure to post a brief reply without revealing your solution to enter the contest!
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One more good question from
egmat. Modifiers at play here. Should not be much of a problem though

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