A student who approaches a teacher with a problem needs a respectful response within professional boundaries.
Why D fits: Reasonable help and encouragement acknowledge the student’s concern without dismissing it.
Why the others are weaker: Immediately contacting parents, forbidding future visits, or sending the student away to the principal may be premature.
Safeguarding point: A home visit raises boundary and safety issues. The teacher should follow school policy, avoid making promises of secrecy, and refer serious concerns through the designated support channels.