The correct answer to this question is B, $10. This question would mainly be found on a math test, focusing on mathematical logic. This logic uses many theories including set, model, recursion, and proof. The study of mathematical logic began in 19th century and was then used in areas of geometry and analysis.

Beyond math, mathematical logic can be used in fields such as law, economics, and history. There are many types of mathematical logics, such as first order logic which uses formulas as an expression. There is also infinitary logic, which uses formulas to provide an infinite amount of information.