Which of the following citrus fruits is not a hybrid?

🍊 Citrus Fruit Classification
→ Tangerine: A true species within the genus Citrus, known as Citrus reticulata, considered the ancestor of many mandarin orange varieties.
→ Grapefruit: A hybrid between pomelo and sweet orange.
→ Lemon: Believed to be a hybrid of citron and bitter orange.
→ Orange: Another hybrid, likely arising from a cross between pomelo and tangerine.