The correct answer is: B. Strong function
Transconductance is a measure of how much current a transistor can source or sink for a given voltage change across its gate. It is a strong function of the gate voltage, meaning that a small change in gate voltage can cause a large change in current. This makes transconductance a useful parameter for designing amplifiers and other circuits that require precise control of current.
Option A is incorrect because transconductance is not a weak function. It is a strong function of the gate voltage.
Option C is incorrect because transconductance is not both a weak and strong function. It is a strong function.
Option D is incorrect because transconductance is a well-defined and measurable quantity. It is not “none of the mentioned.”