x^5+x+1
= x^5 - x^4 + x^4 - x^3 + x^ 3 - x^2 +x^2+x+1
=x^4(x-1) + x^3(x-1) + x^2 (x - 1)+ x^ 2+ x +1
=(x-1)(x^4+x^3+x^2)+(x^2+x+1)
=(x-1)(x^2)(x^2+x+1)+(x^2+x+1)
=(x^2+x+1)(1+(x-1)*x^2)
=(x^2+x+1)(x^3-x^2+1)
So
x^5+x+1=(x^3-x^2+1)(x^2+x+1)
therefore (x^3-x^2+1) is a factore
so option (2) is the right answer