Answer:
Option C is the right answer.
Step-by-step explanation:
Given is a set in roster form as
A={1,2,3....}
This can be represented in set builder form as the set of all natural numbers greater than or equal to 1.
FIrst option is incorrect because x cannot be the set of real numbers.
Second option is also incorrect because here x is not real number
III option is right because x is the set of all natural number which are equal to or greater than 1.
Hence option III is right.
