Consider the following sets and their respective topologies. Which of the following is a topological space based on the definition of topology?
1
Set: {a, b, c}, Topology: { ∅, {a}, {c}, {a, b}, {a, b, c}}
2
Set: {x, y, z}, Topology: {∅, {x, y}, {y, z}, {x, y, z}}
3
Set: {1, 2, 3}, Topology: {∅, {1}, {2}, {3}, {1, 2, 3}}
4
Set: {p, q, r}, Topology: {∅, {p, q, r}}