B

Step 1: Analyze the velocities of particles A, B, and C.
Particle A has a velocity of v_A = (2t^2 + 6) m/s.
Particle B has a velocity of v_B = (3t^2 + 4) m/s.
Particle C has a velocity of v_C = (6t + 4) m/s.
To find the pseudo force on A, B, and C as observed by each other, we consider the relative motions and apply the concept of pseudo forces that appear due to non-inertial frames of reference.
Step 2: For A as observed by B, the velocity of A is greater than B when t increases, leading to a pseudo force on A by B in the negative direction. Hence, for (i), the correct answer is [B].
Step 3: For (ii) on B as observed by C, similar reasoning leads to a negative direction, confirming [B].
Step 4: On A as observed by C, C moves at a higher rate causing the direction to be positive, confirming [C].
Step 5: Finally, on C as observed by A, A experiences zero force due to no acceleration relative to A.
Thus, the complete matches are: i-B, ii-A, iii-C, iv-E.