Clove, the commonly used spice, is obtained from the flower bud. Clove is the dried flower bud of the clove tree, Scientifically known as Syzygium aromaticum. It is a small, reddish-brown, aromatic flower bud that is harvested before it fully opens. The buds are then dried in the sun until they turn a dark brown color.

Option 1: The root is not the source of clove spice. Clove is obtained from the flower bud, not the root of the plant.

Option 2: The stem is also not the source of clove spice. Clove is obtained from the flower bud, not the stem of the plant.

Option 4: The fruit is not the source of clove spice. Clove is obtained from the flower bud, not the fruit of the plant.

Overall, the correct answer is option 3, as mentioned earlier.