During a routine wellness examination, the nurse is trying to determine how well a 5-year-old boy communicates and comprehends instructions. Which of the following is the best specific trigger question to determine the preschooler's linguistic and cognitive progress?
a) "How well does your son communicate or follow instructions?"
b) "Would you say your son has a vocabulary of about 900 words?"
c) "Does your son speak in complete sentences all the time?"
d) "Is your son's speech clear enough that anyone can understand it?"
Answer: "How well does your son communicate or follow instructions?"