Weight of 1 mole of electrons

$\qquad= 9.108 \times 10^{-31} \times 6.023 \times 10^{23}\;kg$

or number of moles of electron in $9.108 \times 10^{-31} \times 10^{23}\;kg$

$\qquad=1mole$

Number of moles of electrons in $1\;kg=\large\frac{1}{9.108 \times 10^{-31} \times 6.023 \times 10^{23}}=\frac{1}{9.108 \times 6.023} \times $$10^{8}\;moles$

Hence d is the correct answer.