Reading Comprehension (RC) | Re: In addition to conventional galaxies, the universe contains

Hey keats,
As per my understanding it's E.
Reasoning - In the given passage end it's been written that astronomers have speculated that the missing baryonic mass might eventually be discovered.
It means that they haven't discovered a way yet.
So, we can infer that they haven't discovered a way till now in reality, but they are speculating a way in future with different options.

Hope it helps.
Not an expert
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