"Domestic Goats Follow Gaze Direction and Use Social Cues in An Object Choice Task," published online in Animal Behavior in January 2005, included information on goats' performance in a bucket-selection task, when cued by a handler who gazed at the correct bucket. If a goat performed at chance level, its score would be 9; each of the goats' performances was tested to see if it performed significantly better than chance on the 18 trials. Tell whether the standardized score z for each of these goats would be positive or negative:
a. Trudi: score 7
b. Weissohr: score 14
c. Stumpfhorn: score 10
d. Weisshuf: score 8