Final answer:
The speaker of the line “Thou shouldst see a workman in't” is Mark Antony, addressing Cleopatra in William Shakespeare's historical play “Antony and Cleopatra.”
Step-by-step explanation:
The quotation “Thou shouldst see a workman in't” pertains to the historical play “Antony and Cleopatra” by William Shakespeare. The correct answer to the question of who is speaking to Cleopatra in this line is Mark Antony (A). This discussion falls within a play that explores the romantic and political dynamics between Mark Antony, a triumvir of Rome, and Cleopatra, the Queen of Egypt. The intricate relationship they forge, which ultimately leads to mutual downfall, is a pivotal aspect of the broader conflicts and power struggles of that historical era, vividly captured by Shakespeare's drama.