Consider the following multiple linear regression model: earnings = ()0 + b1 height + b2 weight + 23 age + b4gender + b5 yearsofeducaticm + 6. Earnings is dened as the individual's annual labor earnings, which is measured in US dollars. Height is the individual's height, measured in inches. Age is the individual's age, measured in years. Gender is the individual's gender. Years of education is the individual's years of education. If the above multiple linear regression model is estimated using data with 346 individuals, then how many degrees of freedom are there? 339 340 346 344