Select the most appropriate meaning of the given idiom.

A black sheep

A disgraceful person

The most appropriate meaning of the idiom "a black sheep" is a disgraceful person. This idiom refers to a member of a group who is different from the rest, especially a family member who does not fit in. The image of a black sheep is one of being rejected or ostracized, and so the idiom is used to describe someone who is considered to be a disgrace to their family or group.

The other options for the meaning of the idiom are not accurate. An important question is a question that is of great significance or importance. A sudden shock is a surprise that is sudden and unexpected. A calm judgement is a judgment that is made without emotion or bias.