Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

Naming customs are different around the world. In most cultures, however, people have at least two names: a family name and a given name. Your given name is the name you receive when you are born. Your family name is the name you share with other people in your family. In the United States, the family name is often called the last name, and the given name is often called the first name. However, the order of the two names is not the same everywhere. For example, in many Asian countries, the family name is first and the given name is second. When two people from different cultures meet, sometimes they use the incorrect name. This can cause embarrassment. Family names can show something about a family's early history. The origin of many English family names is a place, like London, or a job, such as Farmer or Shoemaker. A long time ago, these families probably worked as farmers or shoemakers. Swedish and Danish family names often mean son of. For example, Johansson means son of Johan. In South Korea, there are only about 250 family names. These names go back hundreds of years to very old clans. About half of all Koreans have one of the three most common family names - Kim, Park, or Lee. There is generally no choice about a family name, but there is much more choice about given names. Parents choose their child's name for many different reasons. They may select a name that sounds beautiful or means something special. These names may have meanings like peace or happiness. In some cultures, there may be a connection between children's names and when or how they were born. For example, a Yoruba child in Nigeria might have a name like Sunday or Born on a Sunny Day. In some countries, parents may pay money to a professional baby namer to help them find a good name. They want to find a name that will be lucky for their child. (Source: Jessica William, Making Connection 1, 2nd Ed., Cambridge, 2014)

What does the word "clans" in the passage mostly mean?