Answer:
B. For example
Step-by-step explanation:
The writer has stated something, then stated the cause of the statement. So you would use for example like a showing evidence or proof statement.
You wouldn't use otherwise because it's still on the same topic and not comparing or show any type of cause and effect
To Conclude, would usually be in closing to finalize your research
Nevertheless is usually used when something appears to be wrong or incorrect and the writer is saying... and this can still happen