Rules of View serializability,
- Whichever Transaction performs Read first on variable let say X, It must perform read first on variable X in the Serial schedule.
- Whichever Transaction performs Write last on variable let say X, It must perform write last on variable X in the Serial schedule.
- meanwhile Producer Consumer i.e. Write $\rightarrow $ Read conflict also should match in Serial Schedule.
Now in your question, T4 is writing last so T4 should be last in serial schedule too and T2 is reading first so T2 should be first in the serial schedule.
I am not solving the whole question but your serial schedule looks like T2 $\rightarrow$ . . . other . . .$\rightarrow$ T4. Now check for the 3rd rule.
