Final answer:
In Roger Brown's (1973) Stages of Syntactical and Morphological Development, Stage I corresponds to the age range of 2 to 3 years.
Step-by-step explanation:
In Roger Brown's (1973) Stages of Syntactical and Morphological Development, the age range associated with Stage I is B) 2 to 3 years. During this stage, toddlers are expanding their vocabulary and begin to utter their first words and phrases. Although their speech may still be limited to simple constructs, they can express a wide range of meanings with these small utterances. For instance, a child of this age might use the word "cookie" not just to identify but also to request a cookie. At this stage, the child's speech is becoming more complex and they are starting to use sentences that might be telegraphic but are understandable with key content words.