Assuming a linear regression model is built and the result is as follows: Coefficients P-value Intercept 0.11 0.01 Counter Sales 0.2 001 Drive-through Sales 0.3 0.01 pizza Vs. Caf 0.5 0.81 Burger Vs. Caf 0.4 0.02 What does the insignificant parameter of P-value 0.81 mean? Select one: a. Keep all the variables in the model b. There is no significant different between Pizza and Cafe and we can merge them in one category. c. The burger store is the only significant parameter d. Pizza store is insignificant and we need to delete the pizza store data e. Pizza stores and Cafe are insignificant and wee need to take them out from the model