Which statement describes an endocrine function rather than an exocrine function? a. salivary glands release saliva into the mouth. b. sweat glands release sweat onto the skin c. the pineal gland releases melatonin into the blood. d. esophageal glands release mucus into the esophagus.

The pineal gland releases the melatonin into the blood which describes an endocrine function rather than an exocrine function.  

Option C

Explanation:  

The endocrine gland releases hormones directly into blood which travels through it to reach the target organ. Whereas, the exocrine glands releases their hormones directly into the duct from which they were released to the target area except pineal gland all other gland in the options are the example of exocrine glands.