Answer:
A) Antonyms
Explanation:
In the case of the sentence "Although Amelia was quite lithe, her sister was clumsy and awkward" the unknown word is "lithe" and this is mainly explained by the conjunction "Although " and "her sister was clumsy and awkward" that shows the word "lithe" is the opposite of "clumsy" and "awkward" and indeed "lithe"
The topic sentence introduces the reader to what you will talk about.
B. They announce the main ideas of paragraphs
Answer is A
Explanation:done it before