Make table, point total work for exam with optional questions

Question

I am writing an exam with the exam class, and I am including a single question where the students are supposed to choose only half to answer. There are six total parts, and they answer three.

I automatically calculate the points for each question using

\qformat{Question \thequestion{} (\totalpoints{} \points ) \hfill}

I am displaying the points for each question, as well as the total for the exam, in a table. I can manually get the correct number of total points using \settabletotalpoints{100}

But can I get the specific question's total to show up in the table as only half? I could imagine a solution that simply excluded a given part or question from the total calculation. Is there a way to do that?

\documentclass[addpoints,10pt]{exam}  
\begin{document}  
\qformat{Question \thequestion{} (\totalpoints{} \points ) \hfill}  
\settabletotalpoints{100}  
\gradetable[h][questions]  
\begin{questions}  
\question  
This is the question. Do only one of part A or B. Your choice. Don't do both.  
\begin{parts}  
\part[100]  
This is part A.  
\part[100]   
This is part B.  
\end{parts}  
\end{questions}  
\end{document}  

Answer 1

You can use \noaddpoints and \addpoints as in the following example:

\documentclass[addpoints,10pt]{exam}
\begin{document}
\qformat{Question \thequestion{} (\totalpoints{} \points ) \hfill}
%\settabletotalpoints{100}
\gradetable[h][questions]
\begin{questions}
\question
This is the question. Do only one of part A or B. Your choice. Don't do both.
\begin{parts}
\noaddpoints
\part[100]
This is part A.
\addpoints
\part[100]
This is part B.
\end{parts}
\end{questions}
\end{document} 

Output: