Let us examine the given choices - 

Option A: The sentence starts with the goal ("to reach the destination") but then introduces the action ("followed the route") before explaining the reason ("because he was confused"). This creates a slightly disjointed flow because the cause (confusion) is mentioned after the effect (following the route).

Option B: The phrase "as he became confused" is unnecessarily wordy and indirect. It introduces a causal relationship ("as") but does so in a way that feels less natural than simply stating the man's state of confusion upfront. The phrase "had to follow" implies obligation or compulsion, which is not inherently wrong but adds a layer of meaning that isn’t necessary. The sentence could be more straightforward by simply stating that he followed the route.

Option C: This sentence clearly establishes a simple cause-and-effect relationship between the man's confusion and his action. The cause (confusion) directly leads to the effect (“following the route”), and the sentence is easy to follow. The conjunction "so" efficiently links the cause and effect.

Option D: The phrase "as the man was confused" is inserted awkwardly in the middle of the sentence, breaking the natural flow. This makes the sentence harder to read and less cohesive. Furthermore, see how the sentence starts with "to reach the destination," which is the goal, but then interrupts with the reason for confusion before stating the action. This structure feels less direct and more convoluted.

Hence, between Options B and C, the latter is the better choice.