A - Although he denies them, Dr. Vasequez faced several scandals last year.
A complex sentences must have both a dependent clasuse (although he denies them) and an independent clause (Dr. Vasquez faced several scandals last year.
Options B and D are compound sentences (two independent clauses) and option C is a simple sentence.
Answer:
creative problem solving, strong compensatory skills, persistence
The answer is D: He divides the dog team.
No this is not the krusty crab this is Patrick.