Final answer:
The Bayley Scales of Infant Development contain both mental and motor scales and are used to measure developmental progress in children from one month to 42 months of age. The correct answer is option C.
Step-by-step explanation:
The Bayley Scales of Infant Development are designed to assess developmental functioning in young children. The correct answer to the student's question is option C, which states that the Bayley Scales of Infant Development contain mental and motor scales. These scales are used to track developmental progress in infants and toddlers, generally from one month to 42 months of age. The assessment includes a number of sensory-motor and cognitive tasks that provide information about an infant's development.