This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'In an alaryngeal speech, with fistula based voice prosthesis, which of these prosthesis has the feature of "Loading tool with an instantaneous opening of the oesophagal flange \nSelect and explain. \nA. Blom-Singer Indwelling, B. Provox 2, C. Panje voice button, D. Blom Singer duckbill', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Alaryngeal speech is a speech made using sources other than the glottis in the larynx to create voiced sound. There are three types: oesophagal, buccal, and pharyngeal speech. In oesophageal tracheoesophageal puncture can be made and utilized Provox2 is a diameter indwelling silicone voice prosthesis that can be inseed, immediately after TE puncture (primary or secondary), without the need for temporary stenting. Ref: https://en.m.wikipedia.org/wiki/Voice_prosthesis', 'role': 'assistant'}]