Step 1: Understanding the Concept
The de Broglie wavelength is \(\lambda=\dfrac{h}{p}\), where \(p\) is the momentum.
Step 2: Impulse
Impulse of a particle starting from rest equals its momentum, \(J=\Delta p\).
Step 3: Result
So \(\lambda\propto\dfrac{1}{p}\): inversely proportional to impulse, option (A).
Final Answer:
The wavelength is inversely proportional to impulse.
\[ \boxed{\text{(A) }\text{inversely proportional to impulse}} \]