what's the different when using "plus" and the word "and"?

For example,
the choices to the problem were:
1. Cronkite was known for his honest presentation of the news PLUS his reassuring tone
2.Cronkite was known for his honest presentation of the news AND his reassuring tone

Thanks.

4 answers

They both have about the same meaning.
But then the answer was choice 2.
What was the problem?
The word "plus" is not a conjunction except in informal speech:
http://dictionary.reference.com/browse/plus

The sentence requires a conjunction to join those two phrases.