Which is the correct passive third-person masculine dual after lan?

Negating the Imperfect with Lan and Lam: Subjunctive, Jussive and Full Paradigms

• لَنْ يَفْعَلَا
• لَنْ يُفْعَلَا
• لَنْ يُفْعَلَانِ
• لَنْ تُفْعَلَا