Final answer:
The question lacks the necessary context or data to determine in which grades Will and Claire had class together. More information is required to give a correct answer.
Step-by-step explanation:
Without additional information provided in the question, it is not possible to determine in which grades Will and Claire had class together. The options given are A) 1st and 2nd grades, B) 2nd and 3rd grades, C) 3rd and 4th grades, and D) 4th and 5th grades, but there is no data or context to discern the correct answer. To accurately answer this question, more context is needed, such as a description of a pattern, a reference to shared activities, or any specific data that links Will and Claire to certain grades.