The answer is C. Glue. Heroin is injected, smoked which doesn't show the person inhaling Heroin. Ecstasy are pills and you do not breathe this in. Glue is used by drug-users to sniff which is also called glue-sniffing so this is an inhalant as it involves breathing in the substance.
I would say from my perspective it would be after.
Explanation:
When I run I don't drink water before or during i usually drink after but also it may be before because I do drink water sometimes before but not too much.