Pediatrician: Child psychologists recommend that mothers of one-year-olds not only name objects in the immediate environment, but that they include the color of the object, when applicable. For instance, if a mother hands her child a red ball, she should say, "This is a red ball." Nonetheless, even if mothers began to name the color, instead of simply saying, "This is a ball," no real benefit will be conferred to the child, because studies have shown that children under 18-months old do not grasp the notion of color.
The pediatrician`s argument is most vulnerable to which of the following?
【选项】The range at which children utter their first sentence typically ranges from 15-months to 30-months.
选项是否正确?