**Explanation:**

Boiling point elevation is the phenomenon in which the boiling point of a solvent increases when a non-volatile solute is added to it. It occurs due to the decrease in vapor pressure of the solvent caused by the presence of the solute particles.

The boiling point elevation is directly proportional to the molal concentration of the solute. Therefore, a higher concentration of solute will result in a greater boiling point elevation.

Now let's analyze the given solvents and determine why benzene would result in the maximum boiling point elevation.

**1. Acetone:**
Acetone is a polar solvent with strong intermolecular forces due to the presence of a carbonyl group. It readily forms hydrogen bonds with water molecules. However, it is not as effective in dissolving non-polar solutes. Therefore, a solution of 1 molal concentration of solute in acetone may not result in the maximum boiling point elevation.

**2. Ethanol:**
Ethanol is also a polar solvent capable of forming hydrogen bonds with water. However, it has a lower boiling point compared to benzene. Solutions of 1 molal concentration in ethanol may exhibit a significant boiling point elevation, but it may not be the maximum possible.

**3. Benzene:**
Benzene is a non-polar solvent with weak intermolecular forces. It does not readily form hydrogen bonds with water. However, it is highly effective in dissolving non-polar solutes. This means that benzene can accommodate a larger number of solute particles compared to polar solvents of the same concentration. As a result, solutions of 1 molal concentration in benzene will have a higher boiling point elevation compared to polar solvents.

**4. Chloroform:**
Chloroform is a polar solvent that can form hydrogen bonds with water. However, it has a lower boiling point compared to benzene. Solutions of 1 molal concentration in chloroform may exhibit a significant boiling point elevation, but it may not be the maximum possible.

In summary, benzene is the solvent that would result in the maximum boiling point elevation when a solution of 1 molal concentration of solute is prepared. This is because benzene is a non-polar solvent that can dissolve a greater number of non-polar solute particles compared to polar solvents.

Boiling point is inversely proportional to force of attraction between constituent particles....since benzene is the only non polar compound..it will possess only vanderwalls forces and hence have the max boiling point