When a person with temporal lobe epilepsy is having an epileptic seizure, part of the brain' s temporal lobe produces abnormal electrical impulses, which can often, but not always, be detected through a test called an electroencephalogram (EEG). Ttherefore, although a positive EEG reading -- that is, evidence of abnormal electrical impulses -- during an apparent seizure is a reasonably reliable indicator of temporal lobe epilepsy, __. Of the following, which one logically completes the conclusion above? ['a negative reading is just as reliable an indicator of the presence of temporal lobe epilepsy', 'a positive reading is more frequently an erroneous reading than is a negative one', 'a negative reading does not mean that temporal lobe epilepsy can be ruled out', 'a positive reading can also indicate the presence of other forms of epilepsy']