Final answer:
The severity of an electric shock is determined by the current flow and the body's resistance, meaning that a certain voltage is not inherently hazardous without knowing the resistance it encounters. Therefore, both the current flow and resistance are factors that determine shock severity.
Step-by-step explanation:
The severity of a shock is determined by the current flow through the body and the body's resistance. Voltage alone does not determine how hazardous an electric shock is; instead, it is the combination of voltage and resistance according to Ohm's law (I = V/R). For instance, a person with dry skin has a higher resistance compared to when they are wet, which means the same voltage can produce a harmless current when they are dry, but a dangerous current when wet. Thus, the correct answer to what determines the severity of a shock is both (a) Current flow and (c) Resistance, which makes option d) Both a and c the right choice.
Knowing this, one can understand why a certain voltage is not necessarily hazardous without further information such as the resistance of the path through the body. A high voltage with high resistance can result in a low, harmless current. However, the same voltage with low resistance can produce a much larger and potentially dangerous current.