A doctor collected data to determine the association between age of an infant and its weight. She modeled the equation \( y = 1.25 x \) \( + 7 \) for the line of best fit. The independent variable, \( x \) , is time in months and the dependent variable, \( y \) , is weight in pounds. What does the \( y \) -intercept mean in this context?
A) The infant's starting weight is \( 7 \) pounds.
B) The infant's starting weight is \( 1.25 \) pounds.
C) The infant's weight increases by an additional \( 7 \) pounds for each month.
D) The infant's weight increases by an additional \( 1.25 \) pounds for each month.
