Final answer:
The medical assistant should dispose of blood-contaminated gloves in a biohazard waste container to ensure proper sterilization and prevent infection spread.
Step-by-step explanation:
The medical assistant should dispose of gloves contaminated with blood after a venipuncture procedure in a biohazard waste container. This is because blood and items contaminated with it are considered biohazardous materials that might contain disease-causing organisms and therefore, must be handled with utmost care to prevent the spread of infections. Disposal in designated biohazard waste containers ensures that the contaminated gloves are properly sterilized, usually by autoclaving, before being disposed of. Furthermore, other options like a regular trash container or a specimen transport bag are not appropriate for disposing of biohazardous waste. The red sharps container is specifically for sharp objects such as needles and blades, not gloves. Therefore, the correct choice for the disposal of gloves soiled with blood would be a biohazard waste container (option A).