Why must crime scene notes be taken in pen in a hard$-$bound notebook? $($note: there myy be mare then I correct answer$)$

a$.$ Spiral bound notebooks are just not cool enough for investizators

b$.$ So pages can easily be removed from the notebook

c$.$ To ensure that nothing has been erased or removed

d$.$ The lead from a pencil can be poisoneus

e$.$ So the forensic investigator and the courts can have a permanens record of the scene