Building blocks of a software architecture typically include elements that define the system structure or modularity. An algorithm is essential for defining processes and computations. A component is a crucial architectural element representing modular parts of the system. A class is a fundamental building block in object-oriented designs. A package is a way to organize and group related classes or components, aiding in modularity. Therefore, the correct building blocks of a software architecture are an algorithm, a component, a class, and a package.