Danny, proprietor of restaurant A, looked for a chef. Restaurant A is very famous in Hong Kong and many chefs want to join restaurant A. Danny asked Susanna, a very experienced and competent chef who applied for the post, to attend an interview and demonstrate cooking different kinds of food. Susanna's performance was excellent.

Danny was very impressed by the performance of Susanna and prepared to give her an offer. However, Danny changed his mind and decided to give the offer to a male chef. Susanna learned from Gordon, her friend who worked in the kitchen of restaurant A, that Danny was told by some staff who worked in the kitchen of restaurant A that "a female chef could not work for 6 hours continuously in the kitchen and it is a management problem for a female chef to work in the kitchen where all the chefs are male".

What are the legal grounds that Susanna can rely on in making a claim against Danny in respect of the decision made by Danny.