I have a dependent variable A, which can be perceived from B, C and D. So to say A = function(B,C,D). B, C, D results in A that is known to us. However, I don't know whether B,C and D follow a linear relation or multiplicative or non-linear relation to predict A. My intention is to predict A with lowest MSE(Mean Squared Error). How many and what are the models I should test to infer the best model.
B, C, D all are distributions.