Q: Is purifying water a simple or complicated process?


Read this paragraph and choose the correct option from the provided answers:

Purification of water for drinking and other uses is a complicated process. Heavy metals need to be removed, a process accomplished by addition of carbonates and sulfates. Lead contamination can present major health problems, especially for younger children. Lead sulfates and carbonates are very insoluble, so will precipitate out of solution very easily.

 Choices:

- expensive

- impossible

- simple

- complicated


A:
complicated