To solve this question, the user needs to know about the different registry services used in web services.

The correct answer is:

B. UDDI

Explanation:

UDDI (Universal Description, Discovery and Integration) is a platform-independent, Extensible Markup Language (XML)-based registry for businesses worldwide to list themselves on the Internet. UDDI enables businesses to be found by others that wish to do business with them. The UDDI specification is a core component of Web Services and describes a platform-independent, XML-based registry for businesses worldwide. UDDI allows businesses to register their services and discover the services of others.

Here are the explanations for the other options:

A. WSDL: WSDL (Web Services Description Language) is an XML-based language for describing Web services and how to access them. It is not a registry service.

C. REST: REST (Representational State Transfer) is an architectural style for building web services. It is not a registry service.

D. eb-XML: ebXML (Electronic Business XML) is a standard for exchanging business messages, extending XML to provide a standard method of exchanging business messages. It is not a registry service.

Therefore, the correct option is B. UDDI.