I AM SURE I LOCKED THE DOOR. I CLEARLY REMEMBER ___________ IT....

23. - DE THI THU TN3 NNAMSO 2 23. - DE THI THU TN3 NNAMSO 2
DE THI THU TN3 NNAMSO 2
23. I am sure I locked the door. I clearly remember ___________ it. A. to lock B. to have locked C. locking D. lock