Which of the following is a Welsh symbol associated with strength and courage?

The Red Dragon is a powerful symbol associated with Wales and represents strength and courage. This emblem, known as "Y Ddraig Goch" in Welsh, has historical significance and has been linked to the country for centuries. It appears on the national flag of Wales and is a source of national pride. The imagery of the dragon captures the fierce and resilient spirit of the Welsh people, often being used in folklore and tales that highlight themes of bravery and valor.

The other symbols, while significant in their respective cultures or regions, do not primarily represent Wales or its attributes of strength and courage. The thistle is often associated with Scotland, the rose is emblematic of England, and the lion frequently symbolizes England as well. Thus, the Red Dragon distinctly stands out as the symbol representing the strength and spirit of Wales.