Which of the Following Statements Is True Regarding the Communication

Which of the following statements is true regarding the communication of audit engagement observations?

A) Criteria, condition, cause, and effect must be communicated for material observations only
B) Criteria, condition, cause, and effect must be communicated for material observations and significant deficiencies only
C) Criteria, condition, cause, and effect must be communicated for all engagement observations.
D) Criteria, condition, cause, and effect do not need to be communicated for insignificant observations with adequate compensating key controls.