Step 1: Define the relationship in the given pair: PEN is the primary instrument used by a WRITER to perform their core professional task, which is writing.
Step 2: Apply the same relationship to SCALPEL, asking which option names the professional whose core task requires this instrument as their primary tool.
Step 3: Eliminate options that are not the user of the tool: 'patient' is the person the tool is used on, similar to calling paper the object a pen is used on, not the user. 'Hospital' is a place, not a person, similar to calling a study or office the answer for pen, which is also incorrect since the analogy needs a person, not a place. 'Nurse' typically does not use a scalpel as their primary instrument, that role belongs to a different professional.
Step 4: 'Surgeon' is the professional whose defining tool is the scalpel, exactly parallel to how a pen defines a writer's core task.
Correct option: (3) Surgeon.