This was written to answer an earlier revision of this question.
The facts you have presented do not make out the offence of hostage taking under section 279.1 of the Criminal Code. This would require an intent to induce someone other than the hostage to do something in exchange for the release.
It is, however:
- the tort of false imprisonment, if the blocking of the exit is in fact preventing Person A from departing the lot (i.e. there is no other way for them to walk out)
- the tort of assault
- the criminal offence of forcible confinement (s. 279(2)), if the blocking of the exit is in fact preventing Person A from departing (i.e. there is no other way for them to walk out)
- the criminal offence of assault