Which sentence uses capitalization correctly?
In class, I learned that two-thirds of Egypt is covered by part of the huge sahara desert that stretches across Africa.
In class, I learned that two-thirds of egypt is covered by part of the huge Sahara Desert that stretches across africa.
In class, i learned that two-thirds of Egypt is covered by part of the huge Sahara Desert that stretches across Africa.
In class, I learned that two-thirds of Egypt is covered by part of the huge Sahara Desert that stretches across Africa.