Read the opening paragraph from Yoshi’s research report on netsukes:

According to the International Netsuke (NET-skay) Society, a netsuke is “a small sculptural object . . . used as a toggle to suspend items hung from the sash (obi) of the kimono.” Items hung from the sash included writing sets, medicine containers, tobacco pouches, and purses (The British Museum; The Fitzwilliam Museum), and were collectively referred to as sagemono (sah-GAY-mo-no), or “hanging things” (The British Museum). Netsukes have been in use since approximately 1600. At first, they were simple, functional objects, but over time netsukes developed into exquisite works of art, often carved from ivory, amber, or coral, or cast in bronze (The British Museum). Today, these finely detailed little sculptures can be found in museums and private collections around the world.

Did Yoshi use credible sources, and how do you know?

A.
Yes, he used credible sources, which is clear from the informative tone of the passage.
B.
No, he didn’t use credible sources, because he didn’t refer to specific government or university websites.
C.
No, he didn’t use credible sources, because he didn’t identify specific experts in the subject of netsukes.
D.
Yes, he used credible sources because he referred to organizations with expertise in the subject of netsukes.