If the roots of the equation bx² + cx + a = 0 be imaginary, then for all real values of x, the expression 3b²x² + 6bcx + 2c² is

As, bx² + cx + a = 0 has imaginary roots. So, c² < 4ab
Now, 3b²x² + 6bcx + 2c² = 3(bx + c)² - c² ≥ -c² ≥ -2ab
Hence, option 'C' is correct. Note that the options in the original question were represented by emojis that are not consistently interpreted. The above cleaned options represent the logical interpretation based on the solution.