The hikers did not know how difficult the trail would be. Therefore, they were exhausted and relieved when they finally reached the summit.
Which choice most effectively combines the two sentences at the underlined portion?
The hike on the trail was the hikers' first time, and they did not know how difficult it would be, so
The trail was the first hike the group would be taking, so they did not know how difficult it would be, and
The hikers did not know how difficult the trail would be, so
The hikers, on their first trip up the trail, did not know how difficult it would be, so
Correct Answer: C
Choice C is the best answer. It uses the coordinating conjunction "so" to link the lack of knowledge (cause) with the feeling of exhaustion/relief (effect).
Choice A is incorrect because it adds unnecessary details about it being the "first time." Choice B is incorrect because it changes the subject to "The trail" and is wordy. Choice D is incorrect because "on their first trip" is extra information not in the original text.