Which of the following would you predict using this information?

Imagine that all members of your class have been tested to determine the level of 5-HIAA, a metabolite of serotonin, in their cerebrospinal fluid. Which of the following would you predict using this information?
A ) Male classmates with low 5-HIAA levels will be more aggressive than those with high levels.
B ) Low 5-HIAA levels will be associated with good exam performance.
C ) High 5-HIAA levels will be associated with poor sleep patterns in males.
D ) Male classmates with high 5-HIAA levels may not be alive 10 years from now.
E ) Those with low 5-HIAA levels will be the thinnest persons in the class.