$3-(30$ marks$)$ Assume we have the following log file with immediate updates schema

A$-$ For each case $($case $1,$ case $2),$ show how the recovery process will run, which transaction we need to redo and which transaction we need to undo. Also, what's the value of $\backslash ($ X $\backslash )$ in the database after the recovery process finished.

B$-$ Answer part A given we have checkpoint at time step $4$