Biology 8th Edition by Kenneth Mason ,Jonathan Losos,Susan Singer,Peter Raven,George Johnson

Exercise 8

What would happen to average birth weight if over the next several years advances in medical technology reduced infant mortality rates of large babies to equal that for intermediate-sized babies (see the following figure, red line). Assume that differences in birth weight have a genetic basis.
A) Over time, average birth weight would only increase.
B) Over time, average birth weight would only decrease.
C) Both a and b.
D) None of the above.