Answer:
Simple
Step-by-step explanation:
A simple sentence consists of one clause, with a subject and a predicate. In the sentence given, the subject is only a small percentage of southern Africa and the predicate is is desert.
The rest of the answer choices are incorrect because compound, complex and compound sentences have at least two clauses. Thus, a compound sentence contains two independent clauses, complex sentences possess one independent clause and at least one dependent clause, while compound-complex sentences have at least two independent clauses and one subordinate clause.