Select the most appropriate word to fill in the blank and make a meaningful sentence.

He had his own line of thinking and would defend his views with ______.

conviction

The most appropriate word to fill in the blank is conviction.

The word "conviction" means "a strong belief in something, especially in the face of opposition." This is the most appropriate word because it accurately describes how the person had his own line of thinking and would defend his views even if others disagreed with him.

The other options are not as appropriate.

• Conversion means "the process of changing someone's beliefs." This does not make sense in the context of the sentence, because the person was not trying to change anyone's beliefs.
• Conversation means "a talk between two or more people." This does not make sense in the context of the sentence, because the person was not just talking about his views, he was defending them.
• Convention means "a set of agreed-upon rules or principles." This does not make sense in the context of the sentence, because the person was not following any set of rules or principles, he was simply defending his own beliefs.