The correct answer to what do Bixby's expressions suggest about his character is the last option: He has a natural, highly witty sense of humor.
When Bixby says things like <em>"By the great Caesar's ghost"</em> or <em>"you don't know enough to pilot a cow down a lane"</em>, it becomes clear that he has a <em>funny, comical and somehow inventive character.</em> His expressions are <em>jokes or puns</em> that seem to be <em>natural</em>, they appear to be <em>common or usual in his speech</em> and to come intuitively. So, the correct answer to what the expressions suggest about Bixby's character is that <em>he has a natural, highly witty sense of humor.</em>
The correct answer couldn't be the first option, <em>"He has a large and somewhat imposing personality"</em> because there is <em>nothing imposing about the comments Bixby does</em>. He is, indeed, a little bit acid, but not at all imposing. On the contrary,<em> he asks for Moses' help and says that he believes him.</em> Therefore, the correct answer couldn't be "He has a large and somewhat imposing personality".
The correct answer couldn't be the second option, <em>"He does not get along well with any other people"</em>, because there is <em>nothing on his way of speaking which indicates that his jokes, puns or way of expressing himself are not well excepted by people.</em> On the contrary, he seems to be acid, humorous, <em>but also friendly.</em> Thus, the correct answer couldn't be "He does not get along well with any other people".
The correct answer couldn't be the third option, <em>"He is extremely well read and well educated"</em> because Bixby shows <em>no signs</em> of that. On the contrary, <em>when he speaks, his expressions are informal and conversational.</em> So, the correct answer couldn't be "He is extremely well read and well educated".
