Choose the appropriate preposition in the blank of the following sentense : Eight men were concernde -- the plot.

Concern in দায়ী অর্থে (responsibility for) কোন কিছুতে জড়িত। যেমন : Macbeth and Lady Macbeth were concerned in Duncan's murder. Concern with কোন বিষয়ে সম্পর্কিত/আগ্রহী। যেমন : They were more concerned with their way of life. Concern for উদ্বিগ্ন, যেমন : He did not seen concerned for her safety.