The correct answer is B) Valerius Cordus.
One of the first scientists of the Renaissance to advance taxonomy through firsthand observations was Valerius Cordus.
Valerius Cordus (1515-1544) was a German scientist and physician who wrote one of the most complete books with medical directions on his time. He also identified and classified many plants and herbs that served to elaborate its medical directions. He traveled to many parts of Europe to collect information on plants that later benefited pharmacists and medical doctors.