The 42 Puzzle

"The Answer to the Ultimate Question of Life, The Universe, and Everything" follow the supercomputer, Deep Thought in the book "The Hitchhiker's Guide to the Galaxy" by Douglas Adams, is: 42

Below is the 42 Puzzle:

The answer is 42, but what's the question?

The Puzzle.
Could it be:
  1. How many spheres are in the diagram?
  2. What position in the grid does the Earth occupy?
  3. The barcode on one of the spheres is the number 42 as an Interleaved 2 of 5 barcode
  4. Considering red-hued spheres (red, purple, orange, black) as a '1' and those without as a '0', what number does each line represent in decimal form? (In binary, each line reads '0101010', or '42' in decimal form.)
  5. What number do the blue-tinted spheres (blue, green, purple, black) spell out? (Similar to a colour blindness test.)
  6. What number is represented by Roman numerals spelled out by the yellow-tinted spheres (yellow, orange, green, black) in the first three rows? (XLII = 42)

Hmmm - maybe not Ultimate Questions!!! So what is the question?