[Q]: Given the background: Alkali, or Alkaline, soils are clay soils with high pH (> 8.5), a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico-chemical properties mainly to the dominating presence of sodium carbonate, which causes the soil to swell[1] and difficult to clarify/settle. They derive their name from the alkali metal group of elements, to which sodium belongs, and which can induce basicity. Sometimes these soils are also referred to as alkaline sodic soils. Alkaline soils are basic, but not all basic soils are alkaline. and the situation: Mike grew tomatoes on his parcel of land and so did John. Mike's attempt was very successful, because he adjusted the soil's pH to a viable level for growing vegetables, and John didn't. Both parcels had soils with lots of sodium carbonate in them. John's experiment failed. Answer the following question: Which parcel had a more alkaline soil?
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[A]: John's

[Q]: Given the background: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. and the situation: John studies how chemicals affect environment. He traveled to the Amish country to see their traditional ways of farming. He noticed they don't use any fertilizers or pesticides. He labeled this part of the study as case A. Then he visited a modern farming facility where they use tons of fertilizers and pesticides. He labeled this part of the study as case B. Answer the following question: In which place people might get sick drinking groundwater, case A or case B?
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[A]: case B

[Q]: Given the background: Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure below ). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it. and the situation: Two people went to the eye doctor's office for an annual exam; James had farsightedness, while Bob had myopia. Answer the following question: Which person didn't have lenses focus images farther forward in the eye?
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[A]: Bob

[Q]: Given the background: As time passes, the number of HIV copies keeps increasing, while the number of helper T cells keeps decreasing. The graph in Figure below shows how the number of T cells typically declines over a period of many years following the initial HIV infection. As the number of T cells decreases, so does the ability of the immune system to defend the body. As a result, an HIV-infected person develops frequent infections. Medicines can slow down the virus but not get rid of it, so there is no cure at present for HIV infections or AIDS. There also is no vaccine to immunize people against HIV infection, but scientists are working to develop one. and the situation: Robert and Justin are both patients in the hospital who are suffering complications from their HIV infections. The doctor is trying to get information from both men about their diseases so he can create customized treatment plans for both men. After a few questions, the doctor discovers that Robert has been infected with HIV for many years, while Justin's infection is quite recent. Answer the following question: Who will develop infections less frequently?
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[A]:
Justin