What is the most common hormone produced by this mass?

A 50-year-old female comes to the clinic complaining of headache and difficulty with vision. These symptoms have been present for the past 2 years and got worse 2 weeks ago. Physical and visual field examination was normal. Labs showed increased level of a pituitary hormone. MRI of the hypophysis showed a macroadenoma (as shown below).


What is the most common hormone produced by this mass?
A. GH
B. Gonadotropins
C. Prolactin
D. ADH
E. Oxcytocin