Your technical team leader who you highly respect has identified a design error that will mostly likely interfere with the meeting documented?

D. Develop alternative solutions to the problem.

this is happening frequently , but you did include if cost is involved into the correction of the design error in which case it will be a big problem if alternative solution is not valid i am afraid to call on additional expenses  C. Increase the specified value to set a new performance goal

While this type of mistake is really not normal for a professional setup, the most professional answer is to admit the mistake, and carry on with your tasks. Make sure you update the documents with the right info., and forward it to the concerned parties.

Please do not be smart with your customers, it is better to be clear and corrective rather than elusive and obvious.

Thank you for the invitation. Sorry, I have no clue about this.