Step 1: {Understanding Free Expansion of an Ideal Gas}
In free expansion, the gas expands without doing work and without heat exchange with the surroundings. Since the process is adiabatic, \( q = 0 \), meaning no heat is exchanged.
Step 2: {Work Done in Free Expansion}
Since the expansion is against a vacuum, no work is done on or by the system. Hence, \( w = 0 \).
Step 3: {Temperature Change in Free Expansion}
For an ideal gas undergoing free expansion, there is no change in temperature, so \( \Delta T = 0 \). Thus, the correct answer is (D).