Which of these fruits is NOT a drupe?

In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell of hardened endocarp with a seed (kernel) inside.

The definitive characteristic of a drupe is that the hard, lignified stone is derived from the ovary wall of the flower. Flowering plants that produce drupes include: coffee, jujube, mango, olive, most palms (including açaí, date, sabal and oil palms), pistachio, avocado, white sapote, cashew, and all members of the genus Prunus, including the almond, apricot, cherry, damson, peach, nectarine, and plum.

The boundary between a drupe and a berry is not always clear. Thus, some sources describe the fruit of species from the genus Persea, which includes the avocado, as a drupe and others describe avocado fruit as a berry.