Can someone clarify this statement which appears on a Maths exam paper for me?

'Candidates attempting more than two questions from Section B will be assessed only on their best two attempts.'

The statement above appears on a Mathematics examination paper. There are 3 questions in Section B of the paper.

What I want to know is: Judging from this statement, if I have attempted all of the three questions in Section B, will the examiner mark my answers to all three questions and count the marks of my answers to the two questions which I got the highest marks out of my answers to all three questions, or, will the examiner only mark my answers to two questions, and his decision as to which answers he marked will be by random picking and brief judgment based on neatness of writing hence decided which two were the 'best attempts'?

I answered all three questions and I thought that I did particularly bad on one question while I answered the other two completely correctly. I am worried that the examiner has only marked my answers to two of the questions which includes the one I answered badly, and left out my answer to the question I did perfectly!

As it says 'best 2 attempts' the examiner should mark all 3 and only use the marks for the best 2. If you obviously did much worse in one than the other 2, then the examiner might not bother marking that one properly but they should definitely not pick 2 questions at random to mark.