Question

Natural numbers are part of every other category of number except

Answer 1

By definition, we have:

In mathematics, a natural number is any of the numbers that are used to count the elements of certain sets, as well as in elementary calculation operations. They are those natural numbers that serve to count elements so they are whole.

For example:

1,2,3,4,5,6,7,8,9 ... ∞

By conventional definition it will be said that any member of the next set, ℕ = {1, 2, 3, 4, ...}, is a natural number.

Integers, whole numbers, real numbers, include natural numbers.

Answer:

Natural numbers are part of every other category of number except:

B. irrational numbers.

Answer 2

"Natural numbers" are the counting numbers ... one, two, three, seventy-two, etc.

They're the first group of numbers that children learn, and may well be the
most rational group of numbers you'll ever see.  One thing none of them is
is an irrational number.

           'B'.