(a, b, d)

Explanation:

is correct since the number of ways of distributing identical objects without any restrictions is same as number of non- negative integer solutions.

is correct since if x, y, z respectively be the number of objects of each variety included in a selections then total number of selections must be number of non- negative integer solutions of x + y + z = 5

is correct since if x, y, z be the number of matches won, lost and drawn by a country, then total results of the series must be number of non- negative integer solutions of x + y + z = 5.

is wrong since if the objects are distinct, the number of ways must be 3 5 .