The answer is the last choice, or D.
When you summarize, you're supposed to gather the most important points and rewrite them in a shorter and more simplified fashion. The first three choices include mostly everything you should do when writing a summary. Usually when you summarize, it's for a concluding paragraph, so writing an introductory paragraph wouldn't be it.
Setting is more Time and Location than the others so it would be A. And B
Tense, the overall mood does not seem to be hostile. So i wouldn't say angry. Doesn't seem to be very uplifting either so joyous is out and as for scary i do not think either of them are scared, more like concerned. So i would go with tense
An estimation of Sonia’s stock could be 5,600 (20 x 280). It’s 280 because I rounded the 278 up. Sonia’s stock is worth 5,560 exactly (20x278). Taking the time worth of the Stock Sonia bought (20) and multiplying it by the increase in value of her stock (278).