The correct answer is C) is able to pass current with little opposition. Copper is an excellent electrical conductor because it has very low electrical resistance, allowing current to flow through it with little opposition. This low resistance is due to the high mobility of the free electrons in copper's atomic structure, which can easily move through the material and carry electrical current. The other answer choices are not the primary reasons why copper is commonly used as an electrical conductor. A) is incorrect because copper's resistance actually decreases at lower temperatures, making it a better conductor in colder conditions. B) is irrelevant to the conductivity of copper. D) is also incorrect, as copper's ability to conduct electricity is not directly related to its ability to hold insulation together.