Explanation:

This question refers to the first *high-level* computer language among the given options. **Fortran (b)**, an acronym for FORmula TRANslation, was developed by IBM in the mid-1950s (with the first manual appearing in 1956 and the first compiler in 1957). It is widely recognized as the first successfully implemented high-level programming language, designed primarily for scientific and engineering computations. **Cobol (a)** (COmmon Business-Oriented Language) was developed later, in 1959, for business, finance, and administrative systems. **C (c)** was developed by Dennis Ritchie at Bell Labs between 1969 and 1973. **C++ (d)**, an extension of C, was developed by Bjarne Stroustrup in the late 1970s. Comparing the development timelines, FORTRAN predates all other options as the earliest high-level language listed, making it the correct choice.