Each question can be answered in 4 ways.
For the first selection, we have 4 selections the student can make.
On the second selection, we will have
[tex]\begin{gathered} 4\times4\text{ ways} \\ \Rightarrow4^2\text{ ways} \end{gathered}[/tex]The third selection will have
[tex]\begin{gathered} 4\times4\times4\text{ ways for selection} \\ \Rightarrow4^3\text{ ways} \end{gathered}[/tex]If this goes on, this means that for n selections, the student will have
[tex]4^n\text{ ways for selection.}[/tex]The multiple-choice test in the question has 7 questions. That is
[tex]4^7=16384[/tex]This means that there would be 16,384 ways to answer the test.