Fill in the blank with correct preposition.
It seems someone is knocking __________ your door.​

Correct option is B

The correct preposition is "at", making the full sentence: "It seems someone is knocking at your door."

This is a fixed and standard expression in English. The verb "knock" when used in the context of doors or entrances, typically takes the preposition "at". It signifies the action of making a sound on a surface (usually a door) to seek attention or request entry.

Information Booster

1. "Knock at the door" is a very common and correct collocation in standard English.
2. "At" is generally used with places when the focus is on the point rather than the interior (e.g., at the station, at the door).
3. This phrase can also appear in different tenses: “Someone was knocking at the door,” or “He knocked at her office.”

Additional Information

• (a) to: Incorrect. While “to” is used to express direction or motion (e.g., go to the door), it is not the correct preposition with “knock.”
• Example (correct use of “to”): “She walked to the door.”
• (c) in: Incorrect. “In” implies being inside something, which doesn’t make sense with “knocking” unless the knocking is occurring inside a room, not on the surface of a door.
• Example: “He’s in the room.”
• (d) upon: Though grammatically acceptable in poetic or archaic use, “upon” is rarely used in modern English in this context.
• Example (archaic): “He knocked upon the chamber door.” (Edgar Allan Poe)