Final answer:
Option C, 'A loblolly pine was planted at the White House, and trees were planted in Brazil, Switzerland, and presented to the Emperor of Japan, among others,' best supports the inference that the 'Moon Trees' symbolize America's contribution to understanding the moon.
Step-by-step explanation:
The best textual evidence that supports the inference that the 'Moon Trees' came to be seen as a symbol of America's contribution to understanding the moon is option C: 'A loblolly pine was planted at the White House, and trees were planted in Brazil, Switzerland, and presented to the Emperor of Japan, among others.' This evidence shows that the Moon Trees were not only planted in America but also internationally, symbolizing America's global contribution to understanding the moon.