A patient specimen was Gram-stained upon arrival in the clinical laboratory and revealed both Gram-positive cocci and Gram-negative bacilli.The specimen was cultured on sheep blood agar and chocolate agar,and after incubation,the culture grew only the Gram-negative bacilli.Which of the following is/are a likely explanation(s)for the failure of the Gram-positive cocci to grow?

A)The Gram-negative bacilli may have grown very quickly and overgrew the slower growing Gram-positive cocci.
B)The media used may not support the growth of the Gram-positive cocci.
C)The growth temperature may have enabled the growth of the Gram-negative bacilli but not the growth of the Gram-positive cocci.
D)The Gram-positive cocci may be an obligate anaerobe and was unable to grow in an ambient air incubator.
E)All of the choices are possible explanations.