The drying time between fixed moisture contents within the 'constant rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid )

ANS:B - T

In the constant rate period of drying, the drying process is primarily controlled by the rate of moisture transfer from the interior of the solid to its surface. Assuming drying occurs from all surfaces of the solid, the drying time between fixed moisture contents within this period is proportional to the square of the thickness of the solid, denoted as 𝑇2T2. So, the correct answer would be: 𝑇2T2