What is the meaning of 'futile'?

Which of the following sentences is grammatically correct?

Read the passage: canines may not be the deepest thinkers in the world. but perhaps that's for the best. the life of a dog—sitting alone all day, waiting for everyone to come home—can be pretty boring. super-smart animals would probably get totally stressed out, says university of pennsylvania researcher james serpell. look at it this way: if dogs were any smarter, they probably wouldn't choose to hang around with us. which best describes the tone of the passage?

Correct the sentence below: the pizza delivery boy was neither early nor late he was right on time. a: correct as it is b: the pizza delivery boy was neither early nor late, he was right on time. c: the pizza delivery boy was neither early nor late; and he was right on time. d: the pizza delivery boy was neither early nor late: he was right on time.