The sentence that contains an independent clause is option B) “Norman now has a job at the high school”.
Independent clauses have meaning by themselves and don’t need other words. They have a subject and predicate as a simple sentence.
Option A) is not correct since the clause is incomplete; the part “at the high school” is an adverbial phrase of place that adds meaning to the independent clause.
Option C) is incorrect as the clause “though he is hoping to find work with the country” does not have meaning by itself and needs additional information.
Option D) is also incorrect since the phrase “to find work with the country” is a prepositional clause that modifies the verb “hope”.
Personally i would say D. the word inferior leads me to think that humans would probably have to help them.
Look up the words and try
These usually have words that are not in the dictionary and not used in formal or regular English . They also can involve events that are impossible or not likely to happen in real life