When separating items in a list, a writer should

a end the list with a colon.
b separate the items with colons.
c add a comma after the “and” before the last item.
d add a comma before the “and” before the last item.

D)

Is right because the comma is the between factor that makes you stop  before saying it

D. add a comma before the "and" before the last item.

Explanation:

Example: I need eggs, milk , and bread.

what is a theme?

ans: the implicit idea of a written work of literature is called a theme.

so, the only theme of "birdfoot's grampa" by joseph bruchuc is that as a human being one should always remember the value of every life on earth.

the grampa is stopping the car again and again to save those little toads from washing away in the heavy rain is an act of kindness and humanity.