A factory might emit

pollution.***
smokestacks.
resources.

Which of the sentences below is punctuated correctly?

I have visited three countries including: Spain, Portugal, and France.
I have visited three countries: Spain, Portugal, and France.***
I have visited three countries; Spain, Portugal, and France.
I have visited three countries: including Spain, Portugal, and France.

Both are correct.

The correct punctuated sentence is: "I have visited three countries: Spain, Portugal, and France."

To determine the correct answer, we need to understand the usage of colon (:) in punctuation. A colon is used to introduce a list or an explanation. In this case, the sentence is introducing a list of countries that the person has visited. Therefore, the punctuation mark that should be used is a colon, not a comma or semicolon.

Let's now analyze the other options:
- "I have visited three countries including: Spain, Portugal, and France." This sentence is incorrect because the colon should not be followed by a comma. The correct usage would be "including Spain, Portugal, and France" without the colon.
- "I have visited three countries; Spain, Portugal, and France." This sentence is incorrect because the semicolon is not suitable for introducing a list of items. A semicolon is typically used to separate independent clauses or items in a complex list.
- "I have visited three countries: including Spain, Portugal, and France." This sentence is incorrect because the word "including" is redundant. The colon should introduce the list directly.

Therefore, the correct punctuation in the given options is: "I have visited three countries: Spain, Portugal, and France."