Which planet is known as the 'Blue Planet'?

The question asks: "Ni sayari ipi inayojulikana kama 'Sayari ya Bluu'?" which translates to "Which planet is known as the 'Blue Planet'?"

The correct option is Dunia.

The Earth (Dunia) is often called the Blue Planet because over 70% of its surface is covered by water, which gives it a distinct blue appearance from space.

The final answer is $\text{Dunia}$.