A is correct.
B's mistake is hard to see, but it is there.
C has no punctuation where it's needed.
D sounds like this: "This shovel is old and rusty it is good enough. However, for the little bit of gardening we do." It sounds rushed in the beginning and the mark doesn't help.
I personally would choose D, because if you chart it out, you could weigh both sides and see things clearly.
B. Person "A" said they were going to have a test.
The tone( speakers attitude)can be frightened or grim and the mood (emotional affect the text gives the readers) can be worried or tense.
