Given below is a statement of legal principle followed by factual situation. Apply the principle to the facts and select the most appropriate answer.
Principle: The owner of a land is entitled to the column of air space above the surface ad infinitum. But, the right is restricted to such height as is necessary for the ordinary used and employment of his land, and the structure on it. A had constructed a single-storeyed house on a corner site. He had no intention of building an additional floor. B is neighbour, who ran an internet parlour got a hoarding made, which protruded over A's house at a height of around 6 feet above the terrace. A sues B for trespass.