53.
The answer is: C
Explanation
The correct option is C: can be revoked before it comes to the knowledge of the offeror. This is based on the postal rule of acceptance, which is an exception to the general rule that acceptance must be communicated to the offeror.
The postal rule states that when an acceptance is sent by post, it is deemed to be complete as soon as it is posted, even if it is lost or delayed in transit. This means that the offeror is bound by the contract from the moment the offeree mails the letter of acceptance, regardless of whether the offeror receives it or not.
However, this rule also implies that the offeree can revoke the acceptance before it reaches the offeror, as long as the revocation is communicated to the offeror by a faster means than post, such as telephone or email. This is because the revocation will take effect when it comes to the knowledge of the offeror, which will be earlier than the acceptance.
Therefore, option C is correct and the other options are incorrect. Option A is wrong because acceptance cannot be revoked at any time, only before it comes to the knowledge of the offeror. Option B is wrong because acceptance can be revoked, as explained above. Option D is wrong because acceptance can be revoked even if it reaches the offeror, as long as the revocation is communicated earlier by a faster means.