Passage Summary: Babies make random noises because they haven't learned how to move their mouths correctly yet; since mastering these movements takes years, the speaker concludes that talking is purely a physical skill.

Conclusion: Learning to speak is strictly a matter of developing physical muscle control rather than mental or abstract processing.

Reasoning: Infants lack the physical coordination to produce specific sounds, and it takes several years for children to master the motor skills required for language.

Analysis: This argument makes a massive leap from 'motor control is necessary' to 'motor control is the only thing involved.' To bridge this gap, the author must assume that there isn't a hidden mental or abstract process happening simultaneously that is independent of motor skills. We are looking for an answer that negates the possibility of a mental component being required for speech acquisition. If the argument is to hold, the author must believe that the physical ability to make sounds is the only hurdle to overcome.