Step 1: Understand the concept
In a stationary wave \(y = 2A\cos(kx)\sin(\omega t)\), the quantity \(k = \dfrac{2\pi}{\lambda}\). Nodes and antinodes alternate, and the distance between a node and the next antinode is \(\dfrac{\lambda}{4}\).
Step 2: Find \(k\)
Comparing with \(\cos\left(\dfrac{\pi x}{10}\right)\) gives \(k = \dfrac{\pi}{10}\ \text{cm}^{-1}\).
Step 3: Find the wavelength
\[ \lambda = \frac{2\pi}{k} = \frac{2\pi}{\pi/10} = 20\ \text{cm} \]
Step 4: Result
The node to antinode distance is \(\dfrac{20}{4} = 5\) cm, option (D). The value 10 cm is the distance between adjacent nodes, and 20 cm is the full wavelength.
Final Answer:
The distance is 5 cm. This is option (D).
\[ \boxed{\text{(D) }5\ \text{cm}} \]