题目内容：
What is the epidemiology of parasitic disease? （）
A.It is a science that studies the patterns on occurrence, transmission, prevalence and outcome of parasitic diseases in animal populations.
B.It is a science that studies the patterns on occurrence, transmission, prevalence and outcome of parasitic diseases in most animal populations.
C.It is a science that studies the patterns on occurrence, transmission, prevalence and outcome of parasitic diseases in a certain kind of animal populations.
D.It is a science that studies the routes on occurrence, transmission, prevalence and outcome of parasitic diseases in some animal populations.
参考答案：