Which distinction is correct?

Ṣifāt al-Ḥurūf — Opposing Qualities and Strength Grades

• خ غ ق have istiʿlāʾ without iṭbāq
• All istiʿlāʾ letters have iṭbāq
• Only infitāḥ letters have istiʿlāʾ
• Iṭbāq has seven letters