What phonetic feature of the Egyptian Arabic dialect — absent from Levantine and Gulf dialects — involves shifting the interdental fricatives 'th' and 'dh' to stops?

• A Tha becomes a glottal stop and dhal disappears entirely
• B Tha shifts to sin and dhal to zay
• C Tha and dhal become ta and dal in everyday speech ✓
• D Tha and dhal both shift to the hard emphatic dad

In Egyptian Arabic, the interdental fricatives ث (th as in 'think') and ذ (dh as in 'this') are systematically realized as ت (t) and د (d) in everyday speech — 'three' (thalatha) becomes 'talata', a hallmark phonetic shift of the Cairo dialect.