Which of the following is the incorrect passive voice form of the sentence?

এখানে incorrect passive voice হল The boy threw the ball. কারন এটি active voice form -এ আছে। 

অন্যন্য অপশনগুলোঃ 
(b) The ball was thrown. This is the correct passive voice form of the sentence.
(c) The ball was thrown by someone. - এটি সঠিক passive voice form -এ আছে। 
(d) The ball was thrown to the boy. -এট সঠিক passive voice form বা activei form কোনটিতে নাই।