P-values from K-S tests comparing C/O distributions of exoplanet hosts across radius (a) and period (b) selection. This figure shows the P-values from K-S tests, which assess whether the C/O distributions of short-period and long-period exoplanets are drawn from the same parent population. Panel (a) shows the P-value as a function of the chosen radius boundary for selecting giant planets, with the orbital period boundary fixed at 30 days. The vertical dashed line marks the fiducial radius boundary at R_B = 4R_⊕. Panel (b) shows the P-value as a function of the chosen period boundary for separating short/long-period giant planets, while fixing the radius boundary at R_B = 4R_⊕. The vertical dashed line marks the fiducial period boundary at 30 days.