Which of the following alkynes can be identified and distinguished from the rest of the alkynes on reaction with ammoniacal silver nitrate to give a white precipitate?

Since only terminal alkyne react with ammonical AgNO_3​ and gives white precipitate, only but-1-yne will react with AgNO_3​ and give white precipitate and can be easily identified and distinguished from rest of the given alkynes.