We met rather few people who spoke English.The sentence is:

Explanation

Option A is correct. A complex sentence is defined as having one independent clause and at least one dependent clause. In this case, "we met rather few people" is the independent clause, and "who spoke English" is the dependent clause that provides additional detail. Option B is incorrect because a simple sentence contains only an independent clause with no dependent clauses. Option C is incorrect as a compound sentence requires at least two independent clauses. The provided sentence contains only one. Option D is incorrect since a compound-complex sentence needs at least two independent clauses along with one dependent clause, which this sentence does not have.