**Answer:**

A) a positive ΔH and a positive ΔS

**Explanation:**

**Entropy -
**

In a system, the randomness is measured by the term** entropy .
**

Randomness basically refers as a form of energy that can not be used for any work.

The change in entropy is given by amount heat per change in temperature.

**When solid is converted to gas entropy increases,
**

As the molecules in solid state are tightly packed and has more force of attraction between the molecules, but as it is converted to gas, the force of attraction between the molecule decreases and hence entropy increases.

So,

**The particles of the substance , if are tightly held by strong force of attraction will decrease the entropy ,
**

And

If the particles are loosely held , the entropy will increase .

**And , hence the value for ΔS will be positive . **

The process of conversion of solid to gas , require some energy , and hence , is a endothermic process ,

**Therefore , **

**ΔH is positive . **