Angelina ran a business in Gaborone, which specialised in producing computer software programmes. Refilwe and Basetsana both worked for Angelina for a period of three years. They were both described as self-employed and both paid tax as self-employed persons. Angelina provided all of their specialist computer equipment. Refilwe was required to work solely on the projects Angelina provided, and he had to attend at her premises every day from 9 am until 5 pm. Basetsana usually worked at home and was allowed to work on other projects. Basetsana could even arrange for her work for Angelina to be done by someone else if she was too busy to do it personally. When Angelina lost her most important contract, which Refilwe had been working on, she decided to relocate the business to be closer to her one remaining large contract in Francistown some 400 kilometres away. As a result she told Refilwe and Basetsana that there would be no more work for them.Required:Advise Refilwe and Basetsana who are concerned:

(c) which category each of them is likely to fall into. (2 marks)

所谓“变号操作”是指将一个整数变成绝对值相同、符号相反的另一个整数。假设使用补码表示的8位整数X=10010101，则经过变号操作后结果为 ( )

A．01101010

B．00010101

C．11101010

D．01101011