If specific ehat capacity of a substance in solid and liquid state is proportional to temperature of the substance, then if heat is supplied to the solid intially at `-20^(@)C` (having melting `0^(@)C`) at contant rate. Then the temperature dependence of solid with time will be best represented by:

Options

A.
B.
C.
D.

Explanation

To solve the problem, we need to analyze how the temperature of a solid substance changes over time when heat is supplied at a constant rate, given that the specific heat capacity of the substance is proportional to its temperature.

### Step-by-Step Solution:

1. **Understanding the Problem**:
- We have a solid substance at an initial temperature of -20°C.
- The melting point of the substance is 0°C.
- The specific heat capacity (C) is proportional to the temperature (T), i.e., \( C = kT \) where \( k \) is a constant.
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