【名词&注释】
伤寒杆菌(salmonella typhi)、消化道功能(digestive function)、正常人血清(normal human serum)
[单选题]正常人血清中可有一定量的伤寒杆菌抗体,但一般范围在()
A. "0"抗体<1:40,"H"抗体<1:80
B. "O"抗体<1:80,"H"抗体<1:80
C. "O"抗体<1:80,"H"抗体<1:40
D. "O"抗体<1:80,"H"抗体<1:160
E. "O"抗体<1:40,"H"抗体<1:40