Final answer:
The note 'Code also' is used when two codes may be required to fully describe a medical condition.
Step-by-step explanation:
The note that appears when two codes may be required to fully describe a condition is D) Code also. This instruction indicates that multiple codes are necessary to capture all the information about the condition. For example, if a patient has a disease with both an underlying etiology and multiple body system manifestations, two codes may be required: one for the etiology and one for the manifestation. A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.