[tex]\text{Your answer would be B). 6}\\\\\text{When you multiply 6 by any number, it'll always end up as a even number}\\\text{Even if you m,utliply 6 with an odd number, it'll still}\\\text{ end up as a even number}\\\\\text{If you multiply 5 with an odd number, the number would be odd}\\\\\text{If you multiply 7 with an odd number. the number would be odd}\\\\\text{If you multiply 9 with an odd number. the number would be odd}\\\\\text{Therefore, 6 would be your answer.}[/tex]
