中国大学MOOC: The man in the video is playing the role of a disgruntled passenger, as you can see from the vest he is wearing. Can you guess the meaning of the word disgruntled?

The man in the video is playing the role of a "disgruntled passenger", as you can see from the vest he is wearing. Can you guess the meaning of the word "disgruntled"? A: confident B: dissatisfied and unhappy C: humble D: humorous