The 4 types of secretory cells in the pancreatic islets are not present in the equal percentages. Which of the following represents the correct approximate percentages for the 4 types of islet cells?

A)80% beta cells, 15% alpha cells, 5% delta cells, <1% F cells
B)80% delta cells, 15% alpha cells, 5% F cells, <1% beta cells
C)80% delta cells, 15% F cells, 5% beta cells, <1% alpha cells
D)80% alpha cells, 15% beta cells, 5% delta cells, <1% F cells
E)80% F cells, 15% delta cells, 5% beta cells, <1% alpha cells