Correct Answer:
B. 64
This series consists of two interleaved sequences. The numbers at the odd positions (1st, 3rd, 5th, 7th...) are cubes of consecutive integers, while the numbers at the even positions (2nd, 4th, 6th, 8th...) are squares of consecutive integers.
- Odd positions: 1 (1³), 8 (2³), 27 (3³), the next term is 64 (4³).
- Even positions: 1 (1²), 4 (2²), 9 (3²), the next term is 16 (4²).
Therefore, the missing term in the sequence, following 9, is 64, which is the next cube in the first interleaved series.