Here's a problem to solve: Scientists studying a group of young sage grouse discovered a large percentage were infected with blood parasites. How will these blood parasites most likely affect the young birds?

Among the 4 following options, which is the correct answer?

- A: by mutating the birds' genetic traits
 
- B: by altering the birds' social behaviors
 
- C: by decreasing the birds' overall health
 
- D: by increasing the birds' available energy
 