which of the following sets is equal to {1, 2, 3, ...}?

Answer:
The correct option is 3) {x I x∈N ,x ≥ 1}
Step-by-step explanation:
we need to choose the correct option for the set is equal to {1, 2, 3, ...}
first option the set {x I x∈R ,x > 1}
In this set it includes all real numbers which are greater than 1
since 1 is not included
so, this is not correct option.
second option the set {x I x∈R ,x ≥ 1}
In this set it includes all real numbers which are greater than or equal to 1
In this set 1 is not included but real numbers includes fraction number also
so, this is not correct option.
Third option the set {x I x∈N ,x ≥ 1}
In this set it includes all natural numbers which are greater than or
equal to 1
so, the set contains {1, 2, 3, ...}
Therefore, the correct option is 3) {x I x∈N ,x ≥ 1}