The speaker makes the observation that when he was a boy, —
a he understood the countryside better than he does now
b his feelings about nature were more spontaneous but less deep
he did not have as much physical energy as others his age
d his love of nature was squelched by his city existence
c

C. It reveals that obstacles can be overcome by resilience and determination.

Explanation:

In the frame story, Sindbad is marooned or shipwrecked after he sets sail from Basra with the merchandise. He is able to survive the terrible dangers he encounters by a combination of resourcefulness and luck and returns home with a fortune.

Sindbad's movement from prosperity to loss, experienced during a voyage filled with adventure, and back to prosperity, achieved when he returns home, is repeated in the structure of each tale. The details of the stories of the voyages shed considerable light on seafaring and trade in the East.