1 cup = 8 fluid
So 144 fluid = 144/8 = 16 cups
So 16 cups candle moles she can fill with the recipe.
First term (a1) is -1
recursive formula goes like this

is the nth term

is the term before that
we normally have

we see each term is multipying by -3 to get next one
so that would be

where a1=-1
the 3rd option is correct except that it is the explicit formula
so answer is 2nd one