Review the original item:
Neil's day revolves around sugar,
he anticipates the pastry that he will choose for breakfast, the
candy bar that he will eat for lunch, and the ice cream that he will have
as dinner.
You chose the correct way to fix the error:
Neil's day revolves around sugar,
for he anticipates the pastry that he will choose for breakfast,
the candy bar that he will eat for lunch, and the ice cream that he will
have as dinner.
A good way to fix a comma splice is to use a comma and a coordinating conjunction like for. When you use this method, you must choose a coordinating conjunction that logically connects the two main clauses.
Because for means the same thing as because, it works nicely in the example above.