In a certain code language, 'CASUAL' is written as 'SACLAU' and 'DESIRE' is written as 'SEDERI'. How will 'FALLEN' be written in that language?

Let's analyze the scrambling pattern by dividing the 6-letter word into two halves of 3 letters each:CASUAL:First half: $\text{C A S}\to \text{reversed}\to \text{S A C}$ Second half: $\text{U A L}\to \text{reversed}\to \text{L A U}$ Combined: SACLAUDESIRE:First half: $\text{D E S}\to \text{reversed}\to \text{S E D}$ Second half: $\text{I R E}\to \text{reversed}\to \text{E R I}$ Combined: SEDERIFALLEN:First half: $\text{F A L}\to \text{reversed}\to \text{L A F}$ Second half: $\text{L E N}\to \text{reversed}\to \text{N E L}$ Combined: LAFNEL