Which of the following are true about bacterial superoxide dismutase?

Q. Which of the following are true about bacterial superoxide dismutase?

P. Present in obligate aerobes

Q. Present in facultative anaerobes

R. Present in aerotolerant anaerobes

S. Absent in obligate aerobes

(A) P and Q only                      

(B) P, Q and R only

(C) P and R only                       

(D) Q and S only

Ans: P, Q and R only