Both Heraclitus and Parmenides were pre-Socratic philosophers with conflicting views. However, both share the view that the true essence of reality is more metaphysical than physical. Heraclitus believed in the unity of opposites, while Parmenides believed that change is an illusion and that only the "one" (a singular essence) exists. In their philosophies, the soul (or psuche) plays a central role in understanding reality, as both thinkers considered the soul a significant element in grasping the true nature of the world.
Option (B) is also partially correct, as Heraclitus did emphasize the unity underlying diversity, but Parmenides did not necessarily deny plurality altogether. Therefore, Option (A) captures the essence of both philosophers' views better than Option (B).
\[
\boxed{\text{Option (A) is correct.}}
\]