Form a quartic equation with rational coefficients 3-√2 and 1+2√2 as roots.
a. x^4+8x^3+12x^2-28x-49=0
b. x^4-8x^3+12x^2+28x-49=0
c. x^4-8x^3-12x^2-28x-49=0
d. x^4+8x^3+12x^22+8x+49=0