I would choose foreshadowing because theme is the life lesson and personification is giving human characteristics to non human things.
The correct answer would be choice C
“an unobstructed passage to the Atlantic”
This "unobstructed passage to the Atlantic" allows for access "to every quarter of the world." The ability to reach every part of the word allows for Britain to trade with anyone and everyone. It best supports the thesis that Britain's geographic advantages supported trade. The detail "insular [inward looking] situation" makes Britain seem closed off as it is focused on it being inside itself rather than open to others. "Combined with the command of the seas" indicates that Britain has access to the seas, but doesn't show how far reaching it goes. "Secures our territory from invasion" would be better to prove that Britain is well protected and safe from invading forces.
Wooden door vs glass door
Both are doors, serve the same function
Wooden is stronger
Glass you can see through