please help :)

Question 20 of 35
Which revision corrects the inappropriate shift in verb mood?

People in the neighborhood are wondering what led to the flooding. Were the water pipes too old? Did the freezing temperatures crack the pipes? Tell them if this mess could have been avoided. Who is responsible for repairing the damage? How can we be sure this won't happen again?

O A. Tell them if this mess is being avoided.
B. Have they avoided this mess?
O C. Could this mess have been avoided?
O D. Tell them if this mess was avoided.​