A music major might choose to specialize in

Travel clerkdegree level: certificate or college degree preferred by employersdegree field: travel planning, travel, or tourism licensure and certification: business license may be required; voluntary certifications available construction carpenterrequired education: a high school dimploma and carpentry apprenticeship transportation managerdegree level: bachelor's degree in supply chain management or bachelor's degree in logistics degree field: supply chain management, systems engineering and business licence or certification: no legal requirement for a transportation to become certified but is recommended since certifications demonstrate commitment to excellence and a broader knowledge chief executive degree level: bachelor's degree; mba preferred degree field: liberal arts, business administration, public administration or field of specialty chosen (i.e health care administration)license or certificate: voluntary certification available

Ibelieve the answer is d. 

Answer(a) one needs to learn from experts and be determined to be the best in the field;