The relationship between more than two variables is called____________.
A) Simple correlation
B) Multiple correlation
C) Linear correlation
D) Non-linear correlation

Hint: We have to choose the correct option as answer from the given particular options. We can choose the correct option by using the trial and error method. For that we have to know about given particular correlations. By their definitions we can analyse which is the correct option for the required statement.

Complete step-by-step solution:
Simple correlation:
Simple correlation is a measure used to determine the strength and the direction of the relationship between two variables, $X$ and $Y$. A simple correlation coefficient can range from $ - 1$ to $1$. However, maximum (or minimum) values of some simple correlation cannot reach unity (that is $1$ or $ - 1$).
Multiple correlation:
In statistics, the coefficient of multiple correlation is a measure of how well a given variable can be predicted using a linear function of a set of other variables. It is the correlation between the variable’s values and the best predictions that can be computed linearly from the predictive variables.
Andmore, multiple correlation refers to the strength of the association between the independent variables and one dependent variable. That is the relationship between more than two variables.
Linear correlation:
Correlation is said to be linear if the ratio of change is constant. When the amount of output in a factory is doubled by doubling the number of workers, this is an example of linear correlation. In other words, when all the points on the scatter diagram tend to lie near a line which looks like a straight line, the correlation is said to be linear.
Non linear correlation:
Correlation is said to be non linear if the ratio of change is not constant. In other words, when all the points on the scatter diagram tend to lie near a smooth curve, the correlation is said to be non linear.
Hence, by analysing the above definition we get,

$\therefore $ The option B) Multiple correlation is the correct answer.

Note: Here we used the trial and error method, that is, trial and error is a fundamental method of problem solving. It is characterized by repeated, varied attempts which are continued until success, or until the practice stops trying. Trial and error is also a method of problem solving, repair, tuning, or obtaining knowledge. In the field of computer science, the method is called generate and test (Brute force). In elementary algebra, when solving equations, it is guess and check.