A

Given that the cubical container filled with water is undergoing acceleration, we can analyze the effect of acceleration on the pressure at various points.
Step 1: Understand that fluid pressure in an accelerating system can be analyzed using the concept of effective gravity. In this case, the effective gravity is modified by the acceleration 'a' acting in the container.
Step 2: The pressure difference in a fluid at rest is normally governed by the hydrostatic pressure principle, which operates as $P = P_0 + ho g h$. However, while accelerating, we consider an effective gravitational field given by $g_{eff} = g + a$, where 'g' is the gravitational acceleration and 'a' is the acceleration of the container.
Step 3: For point A, which is located higher than point G, the effective pressure would be lower than at point G due to the differential height and the effects of the container's acceleration.
Step 4: Other pressure relationships can similarly be deduced:
- Point D is above point F, so pressure at D will be less than F.
- Points C and E are at different heights where E is lower than C due to acceleration. >br>- Similarly, for Points H and B, H is lower than B.
Thus, for point A to point G: Pressure at A is less than at G is true, confirming option A.