Explanation:

- Option 1: Protected

This suggests that refugees are safe from harm, which contrasts the idea of absence leading to exploitation.

- Option 2: Vulnerable

This word implies that without a framework, refugees are exposed to risks such as human trafficking. It fits the context of being at risk due to lack of protection.

- Option 3: Secured

Indicates that the refugees are safe and protected, opposite to the context of exploitation risk.

- Option 4: Guarded

Implies being watched over and protected, not fitting with exploitation vulnerability.

- Option 5: Sheltered

Suggests having a place of safety, which does not align with being at risk of exploitation.