Question

while the outpost was isolated and vulnerable, rat said, he always felt a curious sense of safety there.
source: the things they carried
in this sentence, vulnerable means:
○ of long duration; not new
○ susceptible to attack
○ without an occupant
○ limited in size or scope

Explanation:

The sentence describes an isolated outpost, which would logically be at risk of being targeted. The word "vulnerable" here contrasts with the "sense of safety" Rat feels, so it refers to the outpost being at risk of harm. Analyzing the options: the first option describes something long-standing, the third means empty, the fourth refers to small scale, none fit. Only "susceptible to attack" matches the context of an isolated outpost's risk.

Answer:

susceptible to attack