Explanation:

The question asks for the full form of the acronym 'VoIP'. VoIP is a widely recognized telecommunications technology. Option A, 'Voice of Internet Power', is an incorrect expansion; 'of' and 'Power' are not part of the standard acronym. Option B, 'Voice over Internet Protocol', is the universally accepted and correct full form of VoIP. It refers to a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Option C, 'Voice on Internet Protocol', uses 'on' instead of 'over'. While 'on' might seem plausible, 'over' is the precise and established term used in the technology's name, indicating transmission *across* or *via* the Internet Protocol. Option D, 'Very Optimised Internet Protocol', is an entirely incorrect expansion, introducing words not related to the acronym's meaning. Therefore, the accurate and standard full form of VoIP is 'Voice over Internet Protocol'.