For the first sentence, the correct answer for the meaning of "ambiguous" in the context given is:
B. Unclear and open to interpretation.
The CEO's statement being described as "ambiguous" indicates that it was not clear and could be understood in multiple ways, leading to confusion among shareholders.
For the second passage, the type of argument presented is:
A. Ethos.
The speaker, as a doctor, is establishing their credibility and authority on the subject of treatment, which characterizes an ethos argument that appeals to the speaker's qualifications and expertise.