Misleading quiz question regarding selectors?

In this quiz, there is a question asking which selector is the most specific. The options are

• ID Selector
• Class Selector
• Descendent Selector
• Type Selector

The answer was stated to be an ID selector; however, isn't it really a descendent selector? Since it's really a composition of two selectors you could write

body #id {background-color: blue;}

The corresponding id selector would simply be

#id {background-color: red;}

In the above example, the background-color would end up being set to blue because it is more specific. Doesn't that mean descendent selectors can be the most specific?

Using the following CSS in the example code for Psuedo classes, the resulting background-color is blue.

body #tag {
  background-color: blue;
}

#tag {
  background-color: red;
}