Solution:
Given:
[tex]\begin{gathered} f(x)=3^x \\ \\ f(x)\text{ is the number of people that will be contacted} \\ x\text{ is the level of the phone tree} \end{gathered}[/tex]
[tex]\begin{gathered} when\text{ }f(x)=27 \\ 27=3^x \\ \\ Making\text{ the equation have the same base;} \\ 3^3=3^x \\ \\ Since\text{ the bases are equal, equate the exponents.} \\ Hence, \\ 3=x \\ x=3 \end{gathered}[/tex]
This means at level 3, 27 people will be contacted.
Therefore, OPTION A is the correct answer.
