The correct answer is A. disappointed.
Poirot is a fictional detective created by Agatha Christie. He is a Belgian detective who is known for his use of logic and deduction. In the story, Poirot is investigating a murder. He is shown to be a very intelligent and capable detective. However, he is also shown to be impatient and frustrated with the slow progress of the investigation.
The word “disappointed” means to feel unhappy or let down because something did not happen as you wanted or expected. In this case, Poirot is disappointed because the investigation is not going as quickly as he would like. He is also disappointed because he is not able to solve the case as quickly as he would like.
The other options are not correct because they do not accurately describe Poirot’s feelings. The word “dejected” means to feel very sad or discouraged. The word “pathetic” means to be very sad or pitiful. The word “dismayed” means to be very worried or upset. In this case, Poirot is not sad, pitiful, or worried. He is simply impatient and frustrated.