To determine on which planet an object would weigh the most, we'd need to know the gravitational pull of each planet. Since the question assumes the planets are similar in radius, the weight of an object would depend on the mass of each planet.
Weight is calculated using the formula:
\[ \text{Weight} = \text{mass} \times \text{gravitational acceleration} \]
If we don't have specific mass values or gravitational accelerations for each planet, we can't directly determine which one would result in the highest weight for an object.
If you can provide the mass or gravitational information for each of the planets (X, Y, Z, W), we would be able to identify where an object would weigh the most.