Some of the 7- and 8-year-old children in Ms. Crockett's second-grade class are quite energetic and a bit distractible, whereas others are quieter and more attentive. Which one of the following alternatives is most consistent with the textbook's recommendations for how best to think about such diversity in classroom behavior?

a. Remember that by age 8, all students should be expected to sit still for at least 30 minutes at a time.
b. Acknowledge that some 7-year-olds students simply aren't ready for regular second-grade work and should probably have been retained in first grade for another year.
c. Recognize that such differences may be due to built-in temperamental differences that aren't necessarily within students' control.
d. Remember that's it's important to be stricter with the energetic ones than with the quiet ones and to impose harsher consequences when the energetic ones misbehave.