The last answer sets the most formal tone; "Hello! I was very pleased to meet you at the party last week." the rest are very casual.
The answer is b, are.
The reason is because it is the only one that fits in the sentence that makes sense!
B, D, A, C, E, F. Then I, H, J, K, G.
Answer: the three things a writer must use to develop a successful argument are " Logical reasoning, relevant evidence, and persuasive diction
