Option D. He wants to arrive on time.
It is the only option that has subject and predicate.
What happens with the other options.
A) There is no predicate, so you do not know what happen with the Four baby dogs wadding down the path.
B) There is no subject. Who walked the dog?
C) The funniest part of the comedy show ... clearly is also incomplete, you do not know even if this is a subject or a predicate, depends on what you wanted to say.
