Excerpt from Thermometer Pills
Tracy Wilson

Over the past ten years more than two dozen athletes have died from the medical condition known as heatstroke. Heatstroke occurs when the body’s internal temperature becomes so elevated that its cooling system begins shutting down. Who is most at risk? Surprisingly, it is younger athletes. They often either do not recognize or ignore the warning signs until it’s too late. To make matters worse, children’s bodies are much less efficient that adults at cooling themselves. A promising new product hopes to end the, all too common, heatstroke trend. It is called a thermometer pill.
From the context of the first paragraph, which two words are antonyms?
A) condition/heatstroke
B) efficient/promising
C) internal/elevated
D) recognize/ignore