The answer is: D a compound-complex sentence.
Compound complex sentences are made up of at least two independent clauses (which can stand on their own) and at least one dependent clause (which does not express a complete thought). Independent clauses are joined by coordinating conjunctions, such as <em>for</em>, <em>and</em>, <em>nor</em>, <em>but</em>, <em>or</em>, <em>yet</em>, and <em>so</em>. Dependent clauses are introduced by subordinating conjunctions. For example, <em>even though</em>, <em>after</em>, <em>while </em>and <em>if</em>.
In the example sentence, the independent clauses are "The Tracking Party followed their prey to the river" and "there they lost the trail." The dependent clause is "even though they had several bloodhounds with them."
