Final answer:
Children are most capable of using simple sentences like "I see" from 18 to 24 months old, with language skills rapidly improving thereafter. The correct option is D.
Step-by-step explanation:
Children typically become capable of using simple sentences such as "I see" from 18 to 24 months old. Prior to this, they experience various developmental stages beginning with babbling and progressing to one- and two-syllable words.
By around 12 months, toddlers can use one- and two-syllable words to communicate and follow simple commands. As they near two years of age, their vocabulary expands significantly, and they are able to execute more complex verbal requests and begin using simple sentences.
By age three, toddlers are forming short sentences and are asking questions. With every month, their language abilities improve, paving the way for the complex language skills observed in children around five years of age, who can carry on conversations, recognize letters and words, and engage in more sophisticated cognitive tasks.