Step 1: Identify the highest derivative term in the equation.
Step 2: The equation contains the third derivative \( \frac{d^3y}{dx^3} \) and the first derivative \( \frac{dy}{dx} \).
Step 3: Conclusion Since the highest order derivative is \( \frac{d^3y}{dx^3} \), the order of the differential equation is determined by this term.
The order of the differential equation is 3.
Thus, the correct answer is (B) 3.