In a vast ocean region

Answer choices

1. A

   Correct82% picked this

   The agricultural runoff pouring out of the river contributes to the growth of plankton near

   Why this is right

   The follows from the first two premises. In a vast ocean region, AR -causes? ?PH phosphorus levels have doubled in the past few decades due to agricultural runoff pouring out of a large river nearby. The phosphorus stimulates ?PH -causes? ?PL the growth of plankton near the ocean surface. So agricultural runoff AR -causes? ?PL contributes to the growth of plankton.

   Skill tested: Must be True · how this choice captures the argument's function is the move to repeat next time.

   82%
2. B

   Negation9% picked this

   Before phosphorus levels doubled in the ocean region, most fish were able to survive

   This negates the ~?PH -causes? ~?PL -causes? causal chain. ~?O -causes? ~?F

   9%
3. C

   Unsupported Relationship2% picked this

   If agricultural runoff ceased pouring out of the river, there would be no bacteria on the ocean

   The bacteria that devour decaying plankton are not influenced by the causal chain.

   2%
4. D

   Unsupported Comparison1% picked this

   The quantity of agricultural runoff pouring out of the river has doubled in the

   Phosphorus levels have doubled in the past few decades, but that does not mean the quantity of agricultural runoff doubled as well. The phosphorus could be a small portion of agricultural runoff in general.

   1%
5. E

   Too Strong7% picked this

   The amount of oxygen in a body of water is in general inversely proportional to the level of phosphorus

   While phosphorus contributes to the depletion of oxygen, the relationship does not need to be proportional. There could be threshold limits that trigger certain reactions making the relationship less consistent than is implied by the phrase, “inversely proportional.”

   7%