Question 12
If all given weights are distinct, then only one unique MST is possible.
If w1 and w2 are the same and largest among all weights and other weights are distinct, then only one unique MST is possible.
If w1 and w3 are the same and largest among all weights and other weights are distinct, then only one unique MST is possible.
If w1 and w4 are the same and smallest among all weights and other weights are distinct, then only one unique MST is possible.