Final answer:
The minimum amount of current that can stop the heart by causing ventricular fibrillation is 20 mA. Currents below 5 mA are generally harmless but above 10 to 20 mA, the risk increases significantly, necessitating special electrical safety precautions.
Step-by-step explanation:
The minimum amount of current sufficient to cause the heart to fibrillate (a dangerous condition known as ventricular fibrillation) is current levels at and above 10 to 20 milliamps (mA). Currents below 5 mA are generally considered safe and may pass through the body without causing harm. However, at levels of 10 to 20 mA and above, the risk of sustained muscular contractions and the potential for heart stoppage increase significantly. It is important to note that currents as low as 20.0 microamps (µA) can cause ventricular fibrillation if applied directly to the heart during surgery. This indicates that special electrical safety precautions are necessary when working in environments where such exposure to the heart is possible.
Therefore, the correct answer to the question 'What is the minimum amount of current sufficient to stop your heart?' would be option d) 20 mA. It is at this level of current where the heart is at real risk of ventricular fibrillation when electricity passes through the body in an uncontrolled manner.