Hi,
You can do this easily by changing the access event for the radio buttons. I would use a table to make it easier to 'disable' a question based on the answer.
This is my result:
When Answer B is clicked, Question 2 is 'disabled'.
You can see below that i have set mine up with one question and answer radio buttons per row. By using a table, you can just 'disable the whole row rather than having to disable multiple items.
In the Q1 Answer B click event add this:
form1.#subform[0].Table1.Row1.#subform[0].RadioButtonList.#field[1]::click - (JavaScript, client) //Q1 Answer B
this.resolveNode("Row2").access = "protected"; //using protected rather than read only ensures that TAB skips the field when pressed.
Make sure you add the opposite to Q1 Answer A. If the user changes their mind, you need to re-enable Q2
form1.#subform[0].Table1.Row1.#subform[0].RadioButtonList.#field[0]::click - (JavaScript, client) //Q1 Answer A
this.resolveNode("Row2").access = "open"; //open enables the row again
The code does not send focus to Q3 when a selection is made because pressing tab will do that for you.