A radiograph of the mesial aspect of the mandibular right first molar show 2-3 mm of bone loss, yet clinical probing indicate a pocket depth of 6-8 mm. This discrepancy is probably due to the?
Poor angulation used in taking the radiograph
Presence of mandibular tori in the area
Presence of mesial bone masking the destruction
Presence of facial or lingual bone masking the destruction