(a) Yolanda has lost her heartfelt Persian (a cat specie) named Yolo. She loved Yolo very dearly, therefore she posted an advertisement on her a local free community newspaper with its Facebook page on 5 December 2022. The advertisement reads as follows: "LOST CAT, Persian specie, dark brown, 4-year old, photo attached, at the time of missing, she worn with a name tag which reads 'Yolo'. HK$50,000 reward for safe return. Money deposited with East Asia Bank already for the reward". Phillis, who worked as a campaign manager in a Advertising consultancy firm, read the advertisement on 6 December 2022 and found the lost cat named Yolo. She then contacted Yolanda and returned the dearly cat to her on 15 December 2022. However, when Yolanda saw Yolo, she refused to pay the reward to Phillis. The refusal was due to the cat was given by her boyfriend as a gift and on 12 December 2021, Yolanda has broken up with her boyfriend since 6 December 2022. She did not want the lost cat any more as Yolo reminds her the ex-boyfriend. So she placed another advertisement on the same newspaper's Facebook page on 11 December2022. Unfortunately, Phillis did not read and paid attention to the second advertisement on 11 December 2022. If Phillis appointed you as her legal consultant, please advise Phillis the legal rights for claiming the HK$50,000 reward from Yolanda by applying the contract law rules.