Answer:
The match
Explanation:
You can light both the lantern and the candle if you light the match first.
I don't know of this is a homework question, but I answered it anyway :)
Explanation:
McLeod gauge:
It is used to measure very low pressure of gas.It measure gas pressure by the help of mercury(Hg).it measure absolute pressure of gas.
McLeod gauge on the principle of Boyle's law.Boyle's law state that ,at constant temperature the pressure of gas is directly proportional to its volume.From Boyle's law

A sample of gas is taken from vacuum then its pressure is measured by help Hg.
B I guess. since they both have potential to collapse