Using the OLS method the following regression equation was estimated: AND interpret the Beta coefficient for the explanatory variable Non-Checkout Stand Sales. Question 4 options: a) $523.86. For every $1 increase in Non-Checkout Stand Sales, the Checkout Stand Sales increase by $0.11, holding all other variables constant b) $498.08. For every $1 increase in Non-Checkout Stand Sales, the Checkout Stand Sales increase by $0.11, holding all other variables constant c) $498.08. For every $1 increase in Checkout Stand Sales, the Non-Checkout Stand Sales increase by $0.11, holding all other variables constant d) $523.86. For every $1 increase in Checkout Stand Sales, the Non-Checkout Stand Sales increase by $0.11, , holding all other variables constant