Correct elative with an indefinite plural-feminine complement?

Ism al-Tafḍīl: Formation, Comparison, Agreement and Parsing

• Aṭ-ṭālibātu fuḍlayātu ṭālibātin
• Aṭ-ṭālibātu afḍalu ṭālibātin
• Aṭ-ṭālibātu al-fuḍlā ṭālibātin
• Aṭ-ṭālibātu afḍalu ṭālibātun