What is the complete and simple subject in the following sentence?

One of the first advocates of medical hygiene and antiseptics was Ignaz Semmelweis.

Simple subject: One

Complete subject: One of the first advocates of medical hygiene and antiseptics

The complete and simple subject in the sentence "One of the first advocates of medical hygiene and antiseptics was Ignaz Semmelweis" is "One."

To find the complete and simple subject in a sentence, you can follow these steps:

1. Identify the verb of the sentence, which is "was."

2. Ask the question "who?" or "what?" before the verb to find the subject. In this case, the question would be "Who was?"

3. The answer to the question "Who was?" is "Ignaz Semmelweis."

Therefore, the complete and simple subject in the sentence is "Ignaz Semmelweis."