Final answer:
Nushu was a dialect used exclusively by women in certain parts of China, developed as a medium of communication among themselves in a society where they had restricted access to formal education.
Step-by-step explanation:
The written and spoken dialect used by women in portions of China was Nushu. Nushu was a unique form of writing developed and used exclusively among women in Jiangyong County in Hunan province, southern China. It is believed to have been created during a time when women had limited access to formal education and were often not taught to read or write the standard Chinese script. This female-only script allowed women to communicate among themselves, often in the form of poems and stories that expressed personal thoughts and solidarity in a male-dominated society.
Answer: C. Nushu