If two transactions(T1 and T2) uses the same data,
T1(WRITE) --> T2(READ) #T2 reads the data written by T1
Cascading roll back ensures recoverability by rolling back T2 when T1 rollback.(III option is true)
cascadeless schedule ensures one transaction(T2) should come after first transaction(T1) commits.
Hence Cascade less schedule is also recoverable and ensures no roll back of 2nd transaction(T2) as it was postponed.(II option is true)
Strict schedule is more strict which does not allow even,
T1(WRITE) --> T2(WRITE) #T2 wants to write T1's written data
T1(READ) --> T2(WRITE) #T2 wants to write T1's read data
then T2 should come after T1 commits.(I option is true)
option iv: wrong as cascading does not happen in strict schedule.
option v: Not neccessary.