Fill in the Blank with One of the Words or Phrases

Multiple Choice

Fill in the blank with one of the words or phrases listed below. $$\begin{array} { l l l } \text { index rationalizing } & \text { conjugate } & \text { principal square rootcube root midpoint } \\\text { complex numberlike radicals } & \text { radicand } & \text { imaginary unit } \quad \text { distance }\end{array}$$
-The ________of $\sqrt { 3 } + 2$ is $\sqrt { 3 } - 2$

A) radicand
B) imaginary unit
C) index
D) conjugate