Incorrect. The correct answer is to insert a comma and the word "for" in the sentence. So the sentence should be: "I plan to go shopping for Christmas gifts soon, for I have to buy several gifts to mail to friends and family who live out of state."
Your answer is incorrect. The correct answer is to insert a comma and the word "for" after the word "soon." The corrected sentence would be: "I plan to go shopping for Christmas gifts soon, for I have to buy several gifts to mail to friends and family who live out of state."