The correct answer is: A. Newspaper advertisement regarding sale.
An offer is a proposal to enter into a contract. It must be clear, definite, and communicated to the offeree. In the case of a newspaper advertisement, the advertisement is a clear and definite proposal to sell goods at a certain price. The advertisement is also communicated to
the offeree, as anyone who reads the newspaper can see it.The other options are not offers. A display of goods by a shopkeeper in his window with prices marked on them is not an offer, as the shopkeeper is not making a proposal to sell the goods. An advertisement for a concert is not an offer, as the promoter of the concert is not making a proposal to sell tickets. An announcement of reward to the public is not an offer, as the person making the announcement is not making a proposal to pay anyone who finds the person or thing they are looking for.
In conclusion, the correct answer is: A. Newspaper advertisement regarding sale.