Some of the people who ( ) to the party can't come now.A are

用现在完成时被动语态的have been invented是为了表明动作先发于can't come 的.因为先“邀请”,再“来”
再问： 如果有 were invited可以选不？
再答： 如果有 were invited而没有have been invented的话，可以选；若两者都有，后者更为精确，只是出题的人一般水平较高，不会让两者都出现的。