The correct answer is B. SPF 50 with avobenzone and octocrylene.

Polymorphous light eruption (PMLE) is primarily triggered by UVA exposure, especially UVA1 (340–400 nm), which penetrates deeper and through window glass. Avobenzone is one of the few FDA-approved filters that effectively covers the entire UVA1 spectrum. Since avobenzone is photolabile, stabilizing it with octocrylene enhances both durability and photoprotection. Higher SPF (>30) is also recommended for patients with photodermatoses.

Octinoxate and octisalate offer only UVB and partial UVA2 coverage and are ineffective for UVA1, the primary trigger of PMLE. While zinc oxide provides broad-spectrum coverage, at SPF 15 it offers inadequate UVA1 protection for a patient with PMLE. Padimate O is a para-aminobenzoic acid (PABA) derivative primarily protective in UVB; it is poorly tolerated and not recommended due to allergenicity and lack of UVA protection. Iron oxides offer protection in the visible light range (helpful in pigmentary disorders), but titanium dioxide has limited UVA1 absorption. This combination is more appropriate for patients with melasma or postinflammatory hyperpigmentation than PMLE.