From option 1 - Every complex number is the combination of real and imaginary number. But in the option say every complex number can be expressed in the form of a real number which is wrong.

From option 2 - Every natural number is integer but every integer is not natural number. So from option 2 every integer is natural number is not correct.

From option 3 - Every complex number is the combination of real and imaginary number. So, every real number can be written in the complex form, which is correct.

From option 4 - Every integer is real number but every real number is not an integer. from this option every real number is an integer is not correct.

Hence, "option 3" is the correct answer.

Complex numbers are numbers that consist of two parts — a real number and an imaginary number.

The standard format for complex numbers is a + bi, with the real number first and the imaginary number last. Because either part could be 0, technically any real number or imaginary number can be considered a complex number.

Natural numbers: The counting numbers {1, 2, 3, ...} are commonly called natural numbers; however, other definitions include 0, so that the non-negative integers {0, 1, 2, 3, ...} are also

called natural numbers. Natural numbers including 0 are also called whole numbers.

Integers are the collection of whole numbers and negative numbers. Similar to whole numbers, integers also does not include the fractional part.

Thus, we can say, integers are numbers that can be positive, negative or zero, but cannot be a fraction.