Correct option is B
The correct substitution of the highlighted words is (b) "a very colourful illustrated children’s atlas."
Error identification: The adjective order should be "a very colourful illustrated children’s atlas."
Grammatical Rule used: Order of adjectives (opinion, size, age, shape, color, origin, material, purpose).
Corrected sentence: Rimjhim received a very colourful illustrated children’s atlas on her 10th birthday.