Javascript is most likely the answer.
HTML is markup for formatting a page. It is not really a programming language, it is more like advanced punctuation.
Javascript is a programming language. It is used for creating and developing websites and making them interactive.
C++ is sometime the base of programming and is designed for writing huge systems. C++ is also used for writing operating systems, compilers, game engines, browsers and for many other important softwares.
MATLAB is used for data acquisition and mathematical modeling. Almost in all the universities, students and professors use it for research purposes. MATLAB as a scripting language is also very much used for data science analysis. Most of the machine learning and data mining algorithms are already available in it and it is very easy to prototype your analysis MATLAB.