(单选题)

From the text we can infer that _______.

A.The Focus Cap simply blocks unwanted sounds

B.The Focus

C.p can only be used in the office
C. Greblin is confident about the future of his product

D.The Focus Cap has been on sale in quantity

参考答案：C

参考解析：

由最后一段“To be honest, this whole project sounds like a joke, but the Focus Cap does have its own website where people interested in this unusual accessory can actually sign up for updates on when it will go on sale. Greblin claims it will cost 30 euros ($37) plus shipping.”可推知，Greblin对他的这款产品的未来很有信心，选C。

知识点：阅读理解四选一英语专业基础知识阅读理解教师招聘-小学英语