Sentence 8:In fact,most researchers beleive that the ability to discuss problems may be the single most important ingredient in a happy marriage.

What correction should be made to this sentence?

1. remove the comma after fact
2. change the spelling of beleive to believe
3. change discuss to discussing
4. change problems to problem
5. insert a comma after ingredient

2 ?

Right, 2. :-)

To determine the correction that should be made to the sentence, let's analyze the options:

1. Removing the comma after "fact" would not be correct since it is used to set off the introductory phrase "In fact."

2. Changing the spelling of "beleive" to "believe" is the correct correction, as it is the appropriate spelling.

3. Changing "discuss" to "discussing" is not necessary since "discuss" is the correct verb form in this sentence.

4. Changing "problems" to "problem" would be incorrect as it would change the meaning of the sentence, which is referring to multiple problems.

5. Inserting a comma after "ingredient" is unnecessary. The current punctuation is correct since there is no need to separate "single most important ingredient" from the rest of the sentence.

Therefore, the correct correction would be option 2: change the spelling of "beleive" to "believe."