The Mass of Part of a Wire Is $x(1+\sqrt{x})$ Kilograms, Where X Is Measured in Meters from One End

Multiple Choice

The mass of part of a wire is $x(1+\sqrt{x})$ kilograms, where x is measured in meters from one end of the wire. Find the linear density of the wire when x = 16 m .

A) $6 \mathrm{~kg} / \mathrm{m}$ .
B) $6 \mathrm{~kg} / \mathrm{m}$
C) $1.5 \mathrm{~kg} / \mathrm{m}$
D) $4 \mathrm{~kg} / \mathrm{m}$
E) $\text { None of these }$