PLEASE HELP

According to Darwin, why do modern giraffes have long necks?
A
Giraffes have always had long necks like the modern ones.

B
Earlier short-necked giraffes stretched their necks over a long period of time.

C
Ancient giraffes developed short necks and pass this trait to their offspring.

D
Giraffes born with longer necks would survive better in an environment with tall tr