Which is the polynomial function of lowest degree with rational real coefficients, a leading coefficient of 3 and roots √5 and 2?
A)f(x)=3x³-6x²-15x+30.
B)f(x)=x³-2x²-5x+10.
C)f(x)=3x³-21x+30.
D)f(x)=x³-7x+10.