How many continents have a capital A in their names?

Six of the traditional 7 continents have a capital "A" in their English names.

North America

South America

Australia

Asia

Antarctica

Africa

---

Regardless of how one defines a continent, every continent aside from Europe has a capital A in it.

North America

South America

Australia

Antarctica

Africa

Asia

If one chooses to include Central America (normally part of North America or The Americas), it too has a capital A in it.