Final answer:
The phrase 'hat we should be allowed to travel freely abroad' is a sentence fragment; it lacks a main clause which is necessary to express a complete thought. Therefore, the correct option is b. fragments.
Step-by-step explanation:
The student's query appears to be regarding types of sentence structure errors, which includes options like run-on sentences, fragments, non-parallelism, and misplaced modifiers. The correct choice to describe the phrase "hat we should be allowed to travel freely abroad" would be fragments, assuming 'hat' is a typo for 'that'.
A sentence fragment lacks a subject, a verb, or both, or does not express a complete thought. This particular phrase is missing a main clause to make it a complete sentence. For instance, a correct sentence could be: 'The belief that we should be allowed to travel freely abroad is a reflection of our basic freedoms.'