Sublingual salivary gland lies:
Superior to mylohyoid
Inferior to mylohyoid
Deep to genioglossus
Deep to geniohyoid
Sublingual salivary gland:

This is smallest of the three pairs of large salivary glands. 
It lies in the floor of the mouth between the mucus membrane and superior to mylohyoid muscle. 
It is almond shaped and rests in the sublingual fossa of the mandible. 
It is separated from the base of the tongue by the submandibular duct. 
It is mostly mucus in nature and weighs about 3–4 g. 
The gland pours its secretion by a series of ducts, about 15 in number, into the oral cavity on the sublingual fold, but a few of them open into the submandibular duct.

Key Concept:
Sublingual salivary gland is present superior to mylohyoid muscle.