ANS:A - drop panel

The thickened part of a flat slab over its supporting column is technically known as a "drop panel." Explanation: A drop panel, also known as a drop panel slab, is a reinforced concrete slab that includes a thickened area or projection around the supporting column. This thickened area serves to distribute the concentrated loads from the column over a larger area of the slab, reducing the stress and preventing premature failure. It effectively acts as a strengthening element at the column-slab junction. So, the correct technical term for the thickened part of a flat slab over its supporting column is indeed a "drop panel."