开个帖子问个问题，先谢谢大家了：
最近想帮父母办T1 20W的签证，首先就看到了英语成绩的要求。
官网上是说要求CEFR level B1：
You can prove your knowledge of English by either:
passing an approved English language test with at least CEFR level B1 in reading, writing, speaking and listening
having an academic qualification that was taught in English and is recognised by UK NARIC as being equivalent to a UK bachelors degree
但是在在网上很多人都说要求CEFR level C1:cn01:
对父母来说B1还是能办到的，C1就很困难了。有没有最近签过T1同学们，英语成绩要求到底应该是哪个？