Required onlyu when exercise\endexercise is used in the test
description file.
This is used to include just one exercise header when a series of
exercises are lumped together. For instance if a number of true/false
questions are included in a single exam. since each one of this is a
single line question, they can be put all together in a single
exercise. See the command exercise in the test description
file. This macro has to be defined (even if empty) when this option is
used.
Example of \mnexercisestartheader
\newcommand{\mnexercisestartheader}
{Indicate if the following statements are true or false:
\smallskip
}