Final answer:
The offer ends if the offeror revokes it at any time before it is accepted, even if that revocation occurs just seconds before the specified deadline, such as 5 seconds before noon or 0.1 seconds before noon. Other actions mentioned, like an inquiry or insanity of the offeree, do not directly end the offer. The answer is 'C' - the revocation of the offer by the offeror before the specified time.
Step-by-step explanation:
If an offeror makes an offer that states "This offer to be open until noon tomorrow," certain actions can end the offer before the specified time. Specifically, to the option "C) revocation of the offer by the offeror before the time specified (i.e., before noon tomorrow)," this indeed would end the offer if the offeror decided to revoke it, even if it is revoked at 5 seconds before noon or 0.1 seconds before noon. The concept at play here is that an offer can be revoked by the offeror at any time before it is accepted, unless the offer is irrevocable because of a payment or another rule creating an option contract.
In the context of this question, an inquiry by the offeree would not end the offer; it is merely a request for information. The insanity of the offeree could potentially terminate the offer due to incapacity to accept, but it is not explicitly stated. A counter-offer by the offeree would indeed terminate the original offer and create a new offer. Lastly, the selling of the item to someone else before the specified time could also terminate the offer if it reflects the offeror's revocation of the original offer. However, for the purpose of this question, the answer is 'C' - the revocation of the offer by the offeror before the specified time.