null hypothesis question help needed

An analyst constructed the following hypothesis test: H0: b = 0 H1: b > 0 The null hypothesis means that: A. the dependent variable is sensitive to changes in the independent variable. B. the independent variable is sensitive to changes in the dependent variable. C. changes in the dependent variable do not explain changes in the independent variable. D. changes in the independent variable do not explain changes in the dependent variable. Correct Ans is “D”. I never heard of independent and dependent variables and relation between them to come with an answer.

H1 is less than 0. Yet H0 remains static equalling zero.

Is b the coefficient of determination?

It seems to refer to a linear regression