Step 1: Background of the Case:
In the landmark case of Carlill v. Carbolic Smoke Ball Co. (1893), the company advertised that anyone who used their “smoke ball” product as instructed and still contracted influenza would be entitled to £100 as compensation. Mrs. Carlill used the product but still caught the flu and sued the company for the reward.
Step 2: Legal Principle Established:
The Court held that the advertisement constituted a unilateral offer to the public, which could be accepted by anyone who performed the conditions stated in the advertisement. Mrs. Carlill accepted the offer by acting upon it — i.e., by using the smoke ball as instructed — and thus, a valid contract was formed.
Step 3: Final Conclusion:
The correct answer is (B) Acted upon, as the court ruled that performance of the condition specified in the offer amounted to acceptance.