Which sentence is appropriate in a letter to a friend but not in a formal report?

ABrisbane is located about ten hours north of Sydney, Australia.
BIt's a really cool place because it's right on the coast near the beach.
CBrisbane is a popular tourist destination because it is located on the coast.
DMost Americans fly into Sydney and then take a connection from Sydney to Brisbane.

Verified Answer :

BIt's a really cool place because it's right on the coast near the beach.

The wording in this is too casual, so the writing itself is not formal. As well, it provides no useful facts and there is no evidence to support the statement. Therefore it is unfit for a formal report.

Brisbane is a cool place located on the coast near Australia where most Americans fly into.