According to Lionel Robbins, economics is the science that studies human behavior as a relationship between ends and scarce means which have alternative uses.
Economics is a social science because it studies the behavior of people in groups. It is also a personal science because it studies the choices that individuals make.
The correct answer is C. Both A and B.
Option A is correct because economics studies human behavior as a relationship between ends and scarce means which have alternative uses. This means that economics studies how people make choices about how to use their limited resources to satisfy their unlimited wants.
Option B is also correct because economics studies the choices that individuals make. These choices can be about how to spend their money, what to produce, or how to invest their time.
Option D is incorrect because economics is both a social science and a personal science.