What is the difference between an epidemic and an endemic disease? I - An endemic disease is within the expected pattern, with regular frequency a...

What is the difference between an epidemic and an endemic disease?

I - An endemic disease is within the expected pattern, with regular frequency and cyclical or seasonal variations.
II - An epidemic disease is above the expected pattern, with increasing frequency that exceeds the epidemic threshold.
III - The classification of a disease as endemic or epidemic depends on the number of cases.
IV - The classification of a disease as endemic or epidemic depends on the expected pattern of the disease in the last 10 years.
a) Only I and II are correct.
b) Only III and IV are correct.
c) Only I, II, and IV are correct.
d) All statements are correct.