$[40$ pts$.]4.$ Given the following ooncurrent schedule

a$)[5$ pts$.]$ What is the precedence graph for the schedulle? Is the schedule conflict$-$serializable? If so$,$ what is an equivalent serial schedule?

b$)[10$ pts$.]$ If possible, show how a Two$-$Phase Locking might execute following history. $($Hint: A transaction might first obtain a shared lock and then upgrade it to an exclusive lock during its growth phase.$)$

$R1(A)$;$R2(A)$;$R3(B)$;$W1(A)$;$R2(C)$;$R2(B)$;$W2(B)$:$W1(C)$ :

$\backslash$table$[[$T$1,$T$2,$T$3],[,,],[,,],[,,],[,,],[,,],[,,],[,,],[,,],[,,],[,,],[,,],[,,],[,,]]$

c$)[5$ pts$.]$ Comsider the following twio transactions:

T$1$: read$(A$

T$2-$ read$(B)$;Add all necessary lock and unlock instructions to transactions T$1$ and T$2,$ so that they are yrellformed and they observe the two$-$phase lacking protocol.d$)[10$ pts$.]$ Can the execution of these transactions, T$1$ and T$\_(2)$ result in a deadlock? If so$,$ show how a deadlock can be caused.e$)[10$ pts$.]$ If possible, show how a Timestamp Ordering might execute this history or reject it

$\backslash$table$[[$Operation$,A,B,C$