In A: it should be "I was" not "I were".
In B: it should be "lately you appear" not "you appears"
in C: this is correct! the subject is in agreement with the verb, and this is the correct answer.
in D: it should be "you are"
<span>"b. avoided when writing". It could be D, but they can't always be combined this way, so it is best to avoid them.
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