To answer this question, we need to understand the different protocols used for calling web services.
Option A) SOAP - This option is correct. SOAP (Simple Object Access Protocol) is a protocol used for exchanging structured information in web services using XML. It allows applications to communicate and invoke methods remotely.
Option B) HTTP - This option is correct. HTTP (Hypertext Transfer Protocol) is the primary protocol used for communication between a client and a server over the internet. It is widely used to call web services as it allows for the exchange of data between the client and the server.
Option C) RMI-IIOP - This option is incorrect. RMI-IIOP (Remote Method Invocation over Internet Inter-ORB Protocol) is a protocol that allows objects in different Java Virtual Machines to communicate with each other. It is not specifically used for calling web services.
Option D) RPC - This option is incorrect. RPC (Remote Procedure Call) is a protocol that allows a program running on one computer to execute code on a remote computer. While it can be used for distributed computing, it is not commonly used for calling web services.
The correct answer is A, B. Web services can be called over the SOAP and HTTP protocols. SOAP is used for structured communication between applications, while HTTP is the primary protocol for communication over the internet.