Let 3−xx2−6x+10=p
x2−6x+10=3p−px
x2−(6−p)x+10−3p=0
Since the equation will have real roots,
(6−p)2−4×(10−3p)≥0
p2−12p+12p+36−40≥0
p2≥4
p≥2, p≤−2
Now, when p=−2, x=4. Since it is given that x < 3, thus this value will be discarded.
Now, 21 and −21 do not come in the mentioned range.
When p=2, x=2
Thus, the minimum possible value of p will be 2.
Thus, the correct option is C.
Alternate explanation:
Since x < 3,
3 - x > 0
Let 3−x=y. So, y > 0.
Now,
3−xx2−6x+10=3−xx2−6x+9+1
⇒3−x(3−x)2+1
Since 3−x=y, the equation will transform to yy2+1 or y+y1
The minimum value of the expression y+y1 for y > 0 will be at y=1
i.e. Minimum value = 1+1=2
Thus, the correct option is C.