Doors and frames: A wooden strip fixed on the back (stop side) of a door frame post to arrest the door shutter is called a

Introduction / Context:
Door frames commonly incorporate small wood sections that perform distinct functions: stops, horns, cleats, beads, and moldings. Correct terminology prevents confusion in specifications and during site execution.

Given Data / Assumptions:

• A wooden block/strip is fixed to the back side of the door frame posts.
• Purpose is to provide a positive stop for the closing shutter.
• Conventional timber joinery in building works.

Concept / Approach:
The “stop” (also called door stop) is the thin length of timber fixed to the internal face of the frame to prevent the shutter from swinging past the closed position and to provide a sealing line. “Cleats” are small blocks used for fixing or temporary support; “horns” are projecting portions of frames left long for embedding into adjacent masonry; “mullion” separates adjacent window lights, not relevant to doors.

Step-by-Step Solution:
Identify function: restrain the shutter at the closed position.Map function to component → “stop.”Exclude other terms based on their different roles.Choose “Stop.”

Verification / Alternative check:
Standard door frame details show the stop rebated or planted onto the frame for latch strike alignment and for weather or acoustic seals.

Why Other Options Are Wrong:
Cleat: fastening block, not a shutter-arrest strip.Horn: frame extension for embedding in masonry.None/Mullion: do not name the described part.

Common Pitfalls:
Confusing “rebated frame” with planted stop; omitting continuous stop at the head leading to light leakage or poor latch engagement.

Final Answer:
Stop.