While conducting an experiment using pyrophorics, it comes in contact with air and ignites. what kind of extinguisher should be available in the lab?

The correct answer is class D extinguisher.  

The pyrophoric materials refer to the components, which ignite briskly after coming in contact with oxygen. These substances can also be water reactive, where hydrogen and heat get produced. A pyrophoric substance ignites continuously in the air at or below 55 degree Celsius.  

While working on pyrophoric substances, a class D fire extinguisher is used. A class D fire extinguisher is utilized on combustible metals like titanium, magnesium, sodium, and others that need an extinguishing medium, which does not react with the burning metal.  

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)