Bella graduated from Tunku Abdul Rahman University College. She works as a property agent. One of her important clients is Dr Tan, a rich and successful doctor. Dr Tan has many properties. Bella has sold many properties for Dr Tan throughout the years. One day Dr Tan told Bella that he was going to China for two weeks to speak at a medical conference. However, in his absence, he wanted Bella to sell his old vacant bungalow house. Dr Tan told Bella that he wanted the house to be sold at not less than RM3 million and that he wanted to get the proceeds of sales as soon as possible because he needed some money to open another clinic. A few days later, Datuk Kamal, who is a good friend of Dr Tan called Bella to say that he was interested to buy the house. Bella brought Datuk Kamal to inspect the house. Datuk Kamal and Bella found out that the house was very old. The ceiling was leaking and the floor had to be entirely replaced due to termites infestation. Bella knew that the market value of the house was not RM3 million. But Datuk Kamal said he was willing to buy the house for RM2.9 million in cash. Bella knew this was a very good deal. She tried to call Dr Tan in China but Dr Tan did not take up the call. Bella then agreed to accept Datuk Kamal's offer. After that, Dr Satish called up Bella. He told Bella he was Dr Tan's colleague in the hospital. Dr Satish was interested to buy one of Dr Tan's old BMW car for RM100,000. Dr Satish had spoken to Dr Tan directly on this matter but Dr Tan told Dr Satish to liaise with his agent, Bella, to prepare the documents for the sale of the car. On hearing this, Bella prepared and arranged all the necessary paperwork. When Dr Tan came back from his trip, he was very angry at Bella for selling the house at RM2.9 million. He told Bella he will not pay any commission to her. Dr Tan also told Bella he does not intend to pay her anything for the sale of the BMW car although he was aware of the transaction. However, Dr Tan also did not deny the fact that he was the one who spoke to Dr Satish and had passed Bella's contact number to Dr Satish. Advise Bella under the law of agency with reference to relevant statutory provisions and decided cases on the following matters: (a) Discuss the duties of Dr Tan as a principal. (5 marks) (b) Explain whether Bella is allowed to claim the sales commission from Dr Tan in respect of the house since she sold the house at a lower price? (10 marks)