All the cases can be considered within the _______ of the existing rules.

A有拼写错误啊
BD又都在意思上说不过去。

选C constitution
how something is formed from different constituents (= parts):
the constitution of a chemical compound

constitution (LAWS) Show phonetics
noun [C]
(a written document which forms) the set of political principles by which a state or organization is governed, especially in relation to the rights of the people it governs:
Britain has no written constitution.
The Constitution of the United States
Under (= As part of) the union constitution, a new committee must be elected each year.

All the cases can be considered within the framework of the existing rules.
一切情况都可以依据现行的规章加以考虑。

B框架