C. The cyclists had ridden from one end of the island to the other.
B. it conveys the subject of the paragraph.
A topic sentence is the main idea which is the subject of the paragraph.
Example of a sentence that most needs to be revised because it's description is too vague is : we hike two miles uphill in the blooming forest.
Usually, you hike on the mountain not in the blooming forest.
hoep this helps
<span>The farm buildings huddled like the clinging aphids on the mountain skirts, crouched low to the ground as though the wind might blow them into the sea. . .
</span>A scar of green grass cut across the flat. And behind the flat another mountain rose, desolate with dead rocks and starving little black bushes
