Question

essentially, it holds returnees for an indeterminate period of monitoring and then simply lets them go.
source: time
in the sentence above, monitoring has the same or almost the same meaning as:

• specifying
• supervising
• biasing
• fraying

Explanation:

To solve this, we analyze the meaning of "monitoring" (observing/overseeing) and compare with options:

• "specifying" means defining details, not matching.
• "supervising" means overseeing/monitoring, matching "monitoring".
• "biasing" means influencing unfairly, not matching.
• "fraying" means wearing out, not matching.

Answer:

B. supervising