What was the core business that made standard oil a horizontal integrated monopoly

answer; i believe that the correct answer is (d); //declaration of independence; plz check first good luck

ok, but what is your question? as soon as you tell me i will answer your question : )

porter is writing economic history because he is focusing on the cost of developing vaccines.

seeing as no choices were provided, i'll do my best to answer it from knowledge.

job specialization promotes work ethic to the person doing the job. he/she may be strong in the arms and able to lift things, specializing him/her in a job where you lift and carry.