Why did the united states introduce the marshall plan post war era

The United States introduced the Marshall plan after the World War II in order to rebuild Western Europe which had been devastated due to the damages caused by the war. It aimed to stabilize the Europe, curtail the spread of Communism therein and spread and support the democracy.

Marshal Plan was named after US Secretary of State George C. Marshall and it also called as European Recovery Program. Under the Plan, US provided more than $15 billion to rebuild Europe.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.