Diction specifically refers to a speaker's choice of words and how "effective" these words are in achieving a specific goal.
So, your answer here should be B: Meaning and effect of words.
Google search "diction" if you want a definition.
Answer:
d) He bought a cabin to break down for lumber.
Explanation:
Thoreau had a hard time getting lumber, so he acquired a cabin to disassemble and use as a lumber.
I'm not sure but i think D would be correct, hope this helps some :)
