Charles runs a gym and fitness business. In an attempt to boost membership, he posts a notice on the gym's Facebook page that he has a new 'membership renewal incentive scheme'. Under the scheme, annual membership fees are to be reduced by 25% for any members who can demonstrate they have reduced their body mass index over a three-month period. Two months later, Charles decides to withdraw the scheme after he receives some advice from his accountants. He posts a notice on the Facebook page that the scheme will not proceed.

Daisy is a member and has worked hard to reduce her BMI, which her doctor says amounts to 3% by the time she sees the Facebook notice. Daisy complains to Charles that she had agreed to A's offer, that he could not withdraw it unilaterally, and that she was entitled to reduced membership fees.

1. a) Advise Daisy whether she could successfully claim that she had accepted Charles' offer under the scheme before he revoked it?
2. b) Would it make any difference if Charles cancels his Facebook account and withdraws the scheme by way of a notice in the quarterly gym newsletter that is posted to members?