Answer:
B) Boiling it at its boiling point
Step-by-step explanation:
As we know that the heat required to convert the given substance from liquid to vapor at its boiling point is known as latent heat of vaporization
So here we know that
![Q = mL](https://img.qammunity.org/2020/formulas/physics/middle-school/4swgto415889swbdbuaza020yemeslddrt.png)
here we know that
![L = (Q)/(m)](https://img.qammunity.org/2020/formulas/physics/middle-school/tgxipy1b24jg46b0xfs5171gn8941j414c.png)
so it is known as the heat required to boil the given substance of unit mass at its boiling point
so correct answer will be
B) Boiling it at its boiling point