The next term of the series —1, 0, 3, 8, will be

The correct answer is (a) 16.

The series is $-1, 0, 3, 8, 16, \ldots$. Each term is the sum of the previous two terms, plus 2. Therefore, the next term is $8 + 16 = \boxed{16}$.

Option (b) is incorrect because 15 is not the sum of the previous two terms. Option (c) is incorrect because 13 is not the sum of the previous two terms. Option (d) is incorrect because 12 is not the sum of the previous two terms.