A student weighs $30\;kg$. Suppose his body is entirely made of electrons. How any electrons are there in his body? Mass of an electron$= 9.1 \times 10^{-31}\;kg$

Question

$\begin{array}{1 1} a. 3.29 \times 10^{31} \\ b. 3.29 \times 10^{30} \\ c. 3.29 \times 10^{23} \\ d. 3.29 \times 10^{32} \end{array} $