The correct answer is: B. His new employer asked him whether he has done this sort of work before.
The sentence “Have you done this sort of work before?” is in the present perfect tense. The present perfect tense is used to talk about things that have happened in the past but have a connection to the present. In this case, the employer is asking the employee whether he has done this sort of work before because they are considering hiring him for a job that requires this type of work. The employer is interested in the employee’s past experience because it is relevant to the job they are applying for.
Option A is incorrect because the past tense is used. The past tense is used to talk about things that happened in the past and are not connected to the present. In this case, the employer is not talking about something that happened in the past, they are asking the employee about his current experience.
Option C is incorrect because the past perfect tense is used. The past perfect tense is used to talk about things that happened in the past before another event in the past. In this case, the employer is not talking about something that happened in the past before another event in the past, they are asking the employee about his current experience.
Option D is incorrect because the simple present tense is used. The simple present tense is used to talk about things that happen regularly or repeatedly. In this case, the employer is not talking about something that happens regularly or repeatedly, they are asking the employee about his current experience.