请教几个关于８８３３表的填写问题。多谢！

My wife is a first-year H-1b holder (directly from China) and working in a university. We will file 1040 together. Here are three questions with regard to how to fill out the 8833 form:

1) which one should be checked:
a) by Regulation section 6114 or b) by section 301.7701(b)-7 or both?

2) Line 2: List the IRS code provision(s) overruled or modified by the treaty. What is the code or where can I find it?

3) Line 4: List the provision(s) of the limitaiton on benefits article...... What is that?

Greatly appreciate your knowledgealbe answers/reply!