Answer :
It is given that the weight of the barbel is given by:
[tex]f(x)=20x+10[/tex]It says that there are eight pair of weights so x can take values from 0 to 8 and f(x) can take the values as follows:
[tex]\begin{gathered} x=0,f(x)=10 \\ x=1,f(x)=30 \\ x=2,f(x)=50 \\ x=3,f(x)=70 \\ x=4,f(x)=90 \\ x=5,f(x)=110 \\ x=6,f(x)=130 \\ x=7,f(x)=150 \\ x=8,f(x)=170 \end{gathered}[/tex]So the range is:
[tex]\mleft\lbrace10,30,50,70,90,110,130,150,170\mright\rbrace[/tex]Option B is correct.