Ideal gas law presumes non-interacting molecules with negligible volume. However, real gases at high pressures and low temperatures diverge from ideal behavior due to intermolecular forces and finite molecular volume. \( \text{CO}_2 \) exhibits stronger intermolecular forces (van der Waals) than \( \text{O}_2 \), \( \text{N}_2 \), and \( \text{He} \). Consequently, \( \text{CO}_2 \) is most prone to deviate from ideal gas behavior under these conditions. Hence, \( \text{CO}_2 \) is the correct selection.