The correct expression to complete the sentence is ”do you pronounce,” forming the question ”How do you pronounce your name?” Thus, the correct answer is option 3.
• is it pronounced (1): This is incorrect; it does not form a proper question.
• you pronounce (2): This is incorrect; it lacks the auxiliary verb needed for the question.
• do you pronounce (3): This is correct; it forms a grammatically correct question.
• to pronounce (4): This is incorrect; it does not fit the structure of the sentence.