Correct option is B
Explanation of the Correct Answer: · "Trekking through the wilderness" (R) logically begins the sentence.
· "Hikers encountered diverse ecosystems" (Q) follows, as it describes what happened during the trek.
· "From lush forests to" (P) continues the idea of diverse ecosystems.
· "Arid deserts" (O) concludes the sentence, describing the variety of ecosystems.
The correct sequence is RQPO, forming the sentence:
"Trekking through the wilderness, hikers encountered diverse ecosystems, from lush forests to arid deserts."