Step 1: Concept A function is discontinuous at a point if the limit from the left, the limit from the right, or the function value at that point does not exist or are not equal.
Step 2: Meaning For $f(x) = 2^{1/x}$, the exponent becomes undefined when the denominator is zero.
Step 3: Analysis At $x=0$, the right-hand limit ($x \to 0^+$) is $2^{\infty} = \infty$, while the left-hand limit ($x \to 0^-$) is $2^{-\infty} = 0$.
Step 4: Conclusion Since the limits are unequal and the function is undefined at $x=0$, it is discontinuous there.
Final Answer: (A)