Cauliflower (Brassica oleracea var. botrytis) is cultivated for its edible head, often called a "curd."
Botanically, this curd is a modified inflorescence or, more specifically, a pre-floral fleshy apical meristem that has undergone extensive branching and proliferation to form a compact mass of undeveloped flower buds and thickened flower stalks (peduncles).
Let's look at the options:
(1) Modified leaves: While leaves surround the curd, the curd itself is not made of leaves.
(2) Modified flowers: The curd consists of numerous undeveloped flower primordia (rudimentary flower buds), so it's more than just "modified flowers"; it's the entire structure that would have developed into many flowers.
(3) Modified inflorescence: This is the most accurate botanical description. An inflorescence is a flower-bearing shoot system. In cauliflower, this system becomes highly condensed and fleshy before the flowers actually open.
(4) Modified stem: While the curd arises from an apical stem meristem, the edible structure itself is primarily composed of branched floral structures, not just a swollen stem like kohlrabi.
Therefore, the edible portion of cauliflower is a modified inflorescence.
Modified inflorescence