Step 1: Understanding the Concept
For a pipe open at both ends, \(f_{n}=\dfrac{nv}{2L}\) with \(n=1,2,3,\dots\).
Step 2: Fundamental
\(f_{1}=\dfrac{340}{2\times1}=170\) Hz.
Step 3: Allowed values
The resonant frequencies are 170, 340, 510, ... Hz. Hence 85 Hz is not a multiple of 170 Hz.
Final Answer:
The air column cannot resonate at 85 Hz.
\[ \boxed{\text{(D) }85\ \text{Hz}} \]