To calculate the amount of water that should be added to a 80% solution of Sulphuric acid to make it a 50% solution, we can use the concept of dilution.

Dilution is the process of adding solvent (in this case, water) to a solution to decrease the concentration of the solute (in this case, Sulphuric acid). The amount of water added can be calculated using the formula:

C1V1 = C2V2

Where:
C1 = initial concentration of the solution (80%)
V1 = initial volume of the solution (unknown)
C2 = final concentration of the solution (50%)
V2 = final volume of the solution (unknown)

Let's solve the equation step by step:

Step 1: Convert the given percentages to their decimal form:
Initial concentration (C1) = 80/100 = 0.8
Final concentration (C2) = 50/100 = 0.5

Step 2: Substitute the values into the equation:
0.8V1 = 0.5V2

Step 3: Since we want to find the amount of water to be added, we can assume the initial volume (V1) as the total volume of the final solution (V2).
0.8V2 = 0.5V2

Step 4: Simplify the equation:
0.8V2 - 0.5V2 = 0
0.3V2 = 0

Step 5: Solve for V2 (final volume):
V2 = 0 / 0.3
V2 = 0

The final volume (V2) is zero, which means that no water needs to be added to the 80% Sulphuric acid solution to make it a 50% solution. This is because the initial solution is already more concentrated than the desired concentration, so no dilution is required.

Therefore, the correct answer is option 'A', which states that no water needs to be added (0cc).