Final answer:
The correct answer to the question is a lawyer, as the literary examples provided describe characters in discreet and weighty positions often associated with the legal profession.
Step-by-step explanation:
The context of the student's question comes from a literary work and revolves around a character who was in life described as most still, most secret, and most grave. Given the examples quoted, in particular the reference to 'that's the man-here he comes,' which recognizes a person as the lawyer who had previously visited, it suggests that the correct answer to the question is a lawyer. Such a character is described in literature as someone who maintains a high level of confidentiality and gravity in their professional capacity.
Another excerpt mentions an 'eminent lawyer', who enjoys a peaceful life dealing with 'rich men's bonds and mortgages and title-deeds', this also corroborates the previous identification of the character being a lawyer.