Which statement correctly distinguishes taḥammul from adāʾ?

Transmission Formulas and Modes of Hadith Acquisition

• Taḥammul means authenticity and adāʾ means the hadith’s topic
• Taḥammul is acquiring a report; adāʾ is transmitting it and describing the mode
• Taḥammul is only writing a book; adāʾ only reading one
• They are exact synonyms in all contexts