Consider the following two transactions:

$T1=R(B),W(B),R(C),R(A)$

$T2=R(C),R(B),W(A)$

Say that sharing lock, exclusive lock, and unlock actions are inserted by the scheduler, resulting in the following annotated transections:

$T1=x(B),R(B),W(B),S(C),R(C),S(A),U(B),U(C),R(A),$COMMIT,$U(A)$

$T2=x(A),W(A),S(C),R(C),S(B),U(A),R(B),U(C)$

$T2=x(A),W(A),S(C),R(C),S(B),U(A),R(B),U(C),U(B),$COMMIT Assume these two transactions are executed concurrently.

Read the following questions carefully and choose the correct option by entering only A$,$ B$,$ C$,$ or D$.$

The transactions T$1$ and T$2$ are using $$

$$ locking protocol.

A$.$ simplicity

B$.2$PL

C$.$ pre$-$claiming

D$.$ strict $2$PL

$2$ A deadlock can occur when executed transactions T$1$ and T$2$ concurrently. While transaction $T1$ is waiting for the data object A to be releasedby transaction T$2,$ transaction T$2$ tries to obtain object C $,$ and it is blocked because C is already locked by transaction TI $.$

A$.$ False

B$.$ True

$3$ The schedule of transactions T$1$ and T$2$ generated by a scheduler is guaranteed to be $$

A$.$ a serial schedule

B$.$ a recoverable schedule

C$.$ Cascading rollback

D$.$ None of the above