The diagram below shows the number of valid votes obtained by four students who contested for the general secretary of a union. The total num¬ber of valid votes polled was By how many votes the winner defeated the nearest candidate ?

The correct answer is (b).

The winner obtained 180 votes, while the nearest candidate obtained 100 votes. Therefore, the winner defeated the nearest candidate by 80 votes.

The other options are incorrect because they do not represent the difference between the number of votes obtained by the winner and the nearest candidate.

Option (a) is incorrect because it is the difference between the number of votes obtained by the winner and the number of votes obtained by the second-nearest candidate.

Option (c) is incorrect because it is the total number of votes polled.

Option (d) is incorrect because it is the difference between the number of votes obtained by the winner and the number of votes obtained by the third-nearest candidate.