Which is a modification into the spine in a cactus plant? stems leaves buds

The correct answer is leaves, spines are modified leaves.

Explanation:

Cactus have spines, the thorn-like thing, in which replace leaves. These spines lower the surface area of the cacti reducing water loss. These spines are actually advance modified leaves which rise according to their environmental conditions.

The stem of a cactus is also thick and fleshy which allows it to store water. The cacti's stem also has a waterproof waxy kind of layer to help retain more water.

Thus, the spines of a cactus plant are nothing but a modified leaf.

there’s no image attached but i can if you want: )