Look at the structure of the sentence, not just its meaning. It says strength "is" bigger than cosmic energy, using "is" to fuse two different ideas together as if they were one and the same kind of thing.
Rule out rhyme right away, since there is no verse or matching end sound. Personification needs a non-human thing acting like a person, which is not happening, cosmic energy is not "doing" anything human here. Hyperbole is possible since the claim is extreme, but hyperbole is about exaggerating a fact, while this sentence is built as a direct equation between two unlike things, strength and cosmic energy.
That direct, "is" based comparison between two different concepts is the working definition of a metaphor, so the answer is B, metaphor.