Which of the following features was unique in the design of the MacBook Air introduced in 2008?

One unique feature in the design of the MacBook Air introduced in 2008 was its thinness and lightweight design. At the time of its release, the MacBook Air was one of the thinnest and lightest laptops on the market, measuring just 0.76 inches at its thickest point and weighing only 3 pounds. This made it a highly portable and sleek option for users looking for a lightweight laptop.