B

Step 1: Understand the relationship between electric current and magnetic fields. According to Ampere's Law, an electric current flowing through a conductor creates a magnetic field around it.
Step 2: Recall that Lenz's Law relates to the direction of induced current and does not primarily describe the magnetic field around a conductor.
Step 3: Ohm's Law deals with the relationship between voltage, current, and resistance, but it does not address magnetic fields.
Step 4: Maxwell's equations encompass different aspects of electromagnetism but do not specifically define the relationship in question as simply as Ampere's Law does.
Conclusion: Therefore, the correct answer is B: Ampere.