A bank develops the following linear discriminant model of the credit quality (i.e., a higher Z means a better credit quality) based on their own loan database:

Z = 1X1 + 2X2 + 3X3

where X1 is return on asset (net income/total assets), X2 is volatility of sales revenue, and X3 is equity to debt ratio (equity value/long-term debts). Which statement below about the coefficients of three variables is correct?

Select one:

a. 1 is positive; 2 is negative; 3 is positive

b. 1 is negative; 2 is positive; 3 is positive

c. 1 is positive; 2 is positive; 3 is negative

d. 1 is positive; 2 is positive; 3 is positive

e. 1 is negative; 2 is negative; 3 is negative