Verified Answer :

4+9i, since i is a complex number which is the square root of 1. It is the only solution with i in it.

Answer:

Option 3 -  \(4+9i\)                          

Step-by-step explanation:

Given : Options in the figure.

To find : Which of the following is a complex number?

Solution :

Complex number is defined as the number which contains real number along with imaginary number.

The complex number is in the form of a+ib.

Now, we determine one by one.

Option 1 - -7

-7 is the real number not complex.

Option 2 - \(2+\sqrt{3}\)

\(2+\sqrt{3}\) is the real number not complex.

Option 3 - \(4+9i\)

\(4+9i\) is in the form a+ib so it is a complex number.

Option 4 - \(\pi\)

\(\pi\) is the real number not complex.

Therefore, Only option 3 is the complex number.