To solve the equation \(-3x = 348\), you would use the division property of equality. This property states that if you divide both sides of an equation by the same non-zero number, the two sides remain equal.
In this case, you would divide both sides of the equation by \(-3\) to isolate \(x\):
\[ x = \frac{348}{-3} \]
So, the correct choice is the division property.