Final answer:
The most precise technique for specifying requirements is formal languages, as they provide a clear and unambiguous method of description, unlike natural languages, UML, or programming languages like C++.
Step-by-step explanation:
The most precise technique for specifying requirements among the options provided is c. Formal languages. Formal languages are used in computer science and mathematics to provide an unambiguous and exact way of describing the syntax and semantics of computer programs and systems. Unlike natural languages which are prone to interpretation and ambiguity, formal languages consist of symbols and strings that are governed by strict syntax and semantic rules.
For example, a specification written in a formal language can be processed by computers and can be used to verify properties of the system being described, such as consistency and completeness. UML (Unified Modeling Language) is useful for visualizing and designing systems, but it is not as precise or unambiguous as formal languages. C++ is a programming language and not a specification language. Natural languages, although intuitive, are the least precise for specifying requirements because of their inherent ambiguity.