When performing financial analysis which of the following is true in respect of unusual transactions that have the effect of boosting profits, or causing unusal swings in gross profit margins or other key ratios.

a) They should largely be ignored given their one-off nature

b) They may be indicators of fraud and should be referred to financial regulators

c) They should be explored further to ascertain the reasons behind them

d) They should be adjusted out of performance measures used for ratio analysis