Which one of the following is an example of present perfect continuous Tense?

এই টপিকের আরও কিছু প্রশ্ন:

• Just now he ------ his dinner but he says he'll see you when he's finished
• If you had studied harder ________.
• If I were rich I____ travel around the world.
• Which of the following sentences is correct?
• The workers were working on the building. What is the correct tense in this sentence? ...