SAT Practice6fec40ff-b4f1-4439-8f08-ba70ddaff0ed
Practice one SAT question at a time

Questions come from the Bluebook question bank.

1009080706050403020100Manganese to calcium ratio(micromoles per mole)2468101214161820Ratio of Manganese to Calcium in Samplesfrom Alboran Sea and Mauritanian CoastApproximate years before present(in thousands) Alboran Sea Mauritanian coast
  • The following 2 lines are shown:
    • Alboran Sea
    • Mauritanian coast
  • The Alboran Sea line:
    • Begins at 2 thousand, 63.2 micromoles per mole
    • Rises sharply to 4 thousand, 99.5 micromoles per mole
    • Falls sharply to 6 thousand, 68.4 micromoles per mole
    • Rises sharply to 8 thousand, 83.2 micromoles per mole
    • Falls sharply to 10 thousand, 32.5 micromoles per mole
    • Rises sharply to 12 thousand, 57.9 micromoles per mole
    • Falls gradually to 14 thousand, 55.7 micromoles per mole
    • Rises gradually to 16 thousand, 64 micromoles per mole
    • Falls sharply to 18 thousand, 51.6 micromoles per mole
    • Falls sharply to 20 thousand, 41.6 micromoles per mole
  • The Mauritanian coast line:
    • Begins at 2 thousand, 12 micromoles per mole
    • Rises gradually to 4 thousand, 15.4 micromoles per mole
    • Falls gradually to 6 thousand, 14 micromoles per mole
    • Falls gradually to 8 thousand, 13.3 micromoles per mole
    • Rises gradually to 10 thousand, 16.5 micromoles per mole
    • Falls gradually to 12 thousand, 15.8 micromoles per mole
    • Rises gradually to 14 thousand, 19.1 micromoles per mole
    • Falls gradually to 16 thousand, 13.2 micromoles per mole
    • Rises gradually to 18 thousand, 14.7 micromoles per mole
    • Falls gradually to 20 thousand, 12.2 micromoles per mole

The population of the coral Lophelia pertusa declined significantly around 9,000 years ago in the Alboran Sea and around 11,000 years ago near the Mauritanian coast. Using the ratio of manganese to calcium, which inversely correlates with ocean oxygenation levels, marine scientist Rodrigo da Costa Portilho-Ramos and colleagues evaluated whether oxygenation played a role in the declines of L. pertusa. The researchers concluded that oxygenation may have been important in the Alboran Sea but not near the Mauritanian coast, since blank

Which choice most effectively uses data from the graph to complete the statement?