Explanation:

- When someone is taken prisoner to fulfill demands, it usually involves a situation where the person is held against their will until certain conditions are met.

- Option 1: Dealer - A dealer is someone who sells goods or services and has no relevance to the concept of being taken prisoner for demands.

- Option 2: Hostage - A hostage is someone who is held captive by a person or group as leverage to force others to meet certain demands. This directly matches the given definition.

- Option 3: Guest - A guest is someone who is invited and welcomed, which is the opposite of being held against one's will.

- Option 4: Host - A host is someone who receives or entertains guests, not a term related to being taken prisoner.