A

Step 1: When measuring specific gravity of solids, we usually weigh the solid in air to find its weight (W_air) and then weigh it immersed in water (W_water). The specific gravity (SG) is calculated using the formula:

SG = \frac{W_{air}}{W_{air} - W_{water}}

Step 2: If the specific gravity of the solid is less than unity (i.e., the solid is less dense than water), it will float when submerged in water.

Step 3: To accurately determine the specific gravity, a modification is required. Instead of weighing it directly in water, which would give a negative reading (not applicable), we should use a buoyancy method or a container to hold the body submerged without allowing it to float. This might include:

• Using a scale that can be submersible or utilizing a holder that allows for weight measurement while maintaining the solid beneath the water’s surface.
• Alternatively, we could weigh the body in air and then use a different method like Archimedes’ principle to measure the volume of water displaced, thus giving us the buoyant force that can be used to indirectly calculate the weight in water.

Conclusion: The method must be altered by ensuring that the body is held submerged to get an accurate weight in water, or by employing a different technique such as measuring displacement.