Select the correct answer.
Which of these is a non-real complex number?

Answer:
C
Step-by-step explanation:
[tex]\dfrac 83 +\sqrt{-\dfrac 73}\\\\=\dfrac 83 + \sqrt{-1} \sqrt{\dfrac 73}\\\\=\dfrac 83 +i\sqrt{\dfrac 73}~~~~~~;\left[i =\sqrt{-1}\right]\\\\\text{It is now in the standard form of complex number (a+bi).}[/tex]