The answer is A Evaluation
The description talks about Richard's work, it resembles a manager's evaluation -mostly during training processes in some jobs-
Incorrect answers:
B Experience
Experience cannot be used as the correct word because all the information is related to Richard's work if in any case, a person would use experience, the expression should be in my experience working with Richard...
C) Guess
A lot of precise and concise elements are enlisted in this description which does not leave any space for expectations
D) Trial
Trial can only be used in a legal context and we do not have any evidence that this is a legal situation.
C would be your answer there due to it trying to help you visualize the setting
I believe the answer is B it shows how potentially dangerous some diseases can be to people
D answer is gloomy,meaning to express depression