In Rutherford's experiment, α particles were deflected because of

Question

$\begin{array}{1 1} \text{a.electrostatic repulsion between α particles and positively charged part of atom } \\ \text{ b.electrostatic attraction between α particles and positively charged part of atom } \\ \text{ c. electrostatic repulsion between β particles and positively charged part of atom} \\ \text{ d. electrostatic attraction between γ particles and positively charged part of atom } \end{array}$