The most accurate way to describe the excerpt is to choose the option - it is a dependent clause. This means that something needs to be added - you need to finish the sentence so that it becomes an independent clause, and not a subordinate one.
The correct answer is that it is a dependent clause.
A dependent clause, as the name itself says, depends on a larger clause in order to make sense. As you can see in the example above, that clause is incomplete - it needs to be part of a larger, independent clause in order to get a proper meaning. The other options are all complete sentences, which is something the example is definitely not.
Name is a form of identifier of a person and it's easier for our brains to remember "This was John" than "This was that tall guy with dark hair and blue eyes". The other reason is that it's usually kind to exchange names when one has a chat with someone else.
