<prompt>  A patient comes with the HO swelling in the submandibular region. He is diagnosed to have submandibular abscess. The incision to drain the abscess is put 1 cm below the base of the mandible becauseThe submandibular gland appears 1 cm below the mandibleIt is difficult to incise along the margin of the mandibleThe marginal mandibular nerve may be injured if incision is along the base of mandibleTo avoid injury to the cervical branch of facial nerve 