Consider the schedule below. Here, R(*) and W(*) stand for 'Read' and 'Write', respectively. T1, T2, T3, T4 and T5 represent five transactions and ti represents a time slot. 

 

 

Regarding the following questions. Give and justify your answers. 

Assume a checkpoint is made between t10 and t11, what should be done to the five transactions when the crash happens between t15 and t16. 

T1 T2 T3 T4 T5 t t2 t3 t4 t3 t4 ts to t7 ts t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 R(B) R(A) W(B) W(A) R(A) R(D) R(C) W(D) R(D) R(C) W(D) W(C) W(A) W(C) R(A) W(A) R(B) Each transaction begins at the time slot of its first operation and commits right after its last operation (same time slot).