ISI2016-MMA-29

Question

Suppose $a$ is a real number for which all the roots of the equation $x^4 -2ax^2+x+a^2-a=0$ are real. Then

• A. $a<-\frac{2}{3}$
• B. $a=0$
• C. $0<a<\frac{3}{4}$
• D. $a \geq \frac{3}{4}$