Which of these statements is true about the respiratory system of cockroach?

Which of these statements is true about the respiratory system of cockroach?
A. Exchange of gases takes place through active transport
B. Sphincters are present at the openings of spiracles
C. There are 8 pairs of spiracles
D. Spiracles are absent on the lateral sides of the body

Answer:
B. Sphincters are present at the openings of spiracles