Of the following, the copper conductor that has the least resistance must be:

Explanation

The correct answer is Thick, short and cool because resistance is inversely related to the cross-sectional area and directly related to the length of the conductor. A thicker conductor (larger cross-sectional area) lowers resistance, while a shorter conductor reduces the path for current flow. Cool temperatures decrease the resistivity of copper, contributing to even lower resistance. In contrast, the options Thin, long and hot, Thick, long and hot, and Thin, short and cool do not meet all criteria for minimizing resistance. The first option suffers from both thinness and length, the second has increased length and temperature, and the last option, despite being short and cool, is thin which increases resistance.