在下列NaCl的物质的量浓度中，DNA溶解度最低的是 [ ]

A．2mol/L

B．0.1mol/L

C．0.14mol/L

D．0.015mol/L

Which of the following statements can be inferred from the graph ？（）
Ⅰ．School X has a smaller enrollment than School Y.
Ⅱ．If the age of a book is the number of years since purchase, then the average (arithmetic mean) age of a book in the School Y inventory is less than that of a book in the School X inventory.
Ⅲ．According to the inventory, School X and School Y purchased the same number of textbooks in 1976.

A．None

B．Ⅰ only

C．Ⅱ only

D．Ⅰ and Ⅱ

E．Ⅱand Ⅲ