The correct option is D x2−7x+12=0 has roots of the same sign
(i) x2+5x+6=0
Here a,b,c are of the same sign
⇒ The roots will be negative
(ii) −3x2−x+2=0
Here a.c=(−3)(2)=−6<0
⇒ The roots will be of opposite sign
(iii) x2−7x+12=0
Here a.c=(1)(12)=12>0
⇒ The roots will be of the same sign