Binh is a young trainee who works for the customer service team in the Relax Hotel. While helping Sell Limited, a corporate client, to set up a meeting room for a conference, she accidentally dropped expensive equipment belonging to the client, causing irreparable damage. As a result, the client could not deliver the presentation as scheduled, causing considerable embarrassment.Sell Limited claimed that its reputation has suffered, as the audience included several valuable customers. In addition, it had to replace the equipment at a cost of 150 million dong.Required:Discuss the obligations of Binh and the Relax Hotel for the losses suffered by the client. (10 marks)

公钥密码体制和对称密码体制是两个不同的密码体制。当n(n很大)个用户采用对称密码进行保密通信时，任意两个用户之间都需要一个安全的信道，系统中共有 (15) 个密钥，每个用户需要持有 (16) 个密钥：而当n个用户采用公钥密码方法进行保密通信时，共有2n个密钥，每个用户需要持有 (17) 个密钥(公开的，可任意使用的公钥不算在内)。

A．n

B．n-1

C．2n

D．2n-2