Answer:
B. Lock contention due to system-initiated sharing rule recalculation
Step-by-step explanation:
By default all spreadsheet cells are locked. We are dealing with different fields here. And for each of them we have different sharing rules which is being initiated by the system. Hence, there will be a case like Lock contention because of the system-initiated sharing rule calculation. Hence there is going to be an error, and the cause is as above.