set X = {a,b,c,d}

These are the three collections of subsets:

1 = { empty set, X, {a}, {b}, {a,b}, {a,c,d}, {b,c,d}, {c,d} }

2 = { empty set, X, {a,b}, {c,d} }

3 = { empty set, X, {a,b}, {b}, {b,c,d} }

Which of 1,2 and 3 are Hausdorff and why?

PS if there is any ambiguity in what I've written, then just notify me and I will try to clarify.