The correct options are
A Avoid harsh climatic conditions
B Food
C Breeding
D Nesting
Migratory birds fly to far away areas every year during a particular time. They might migrate in order to avoid harsh climatic conditions. They also fly for laying eggs as the weather in their natural habitat becomes very cold and inhospitable. Some birds also migrate in search of food and shelter (nesting), while some species migrate for breeding and laying eggs.