"Sources of Individual Shy-Bold Variations in Antipredator Behaviour of Male Iberian Rock Lizards," published online in Animal Behavior in 2005, considered a variety of traits and measurements for lizards noosed in the mountains of central Spain, as well as their behavior under controlled low-risk and high-risk situations.16 Tell whether each of these variables is explanatory or response, and whether it is quantitative or categorical.

a. Whether the lizard was subjected to a "low-risk" treatment (the experimenter walked slowly alongside the terrarium) or a "high-risk" treatment (the experimented approached the terrarium rapidly and tapped the lizard's tail with a brush)

b. The number of blue spots a lizard had on its sides (a possible indicator of vulnerability to predators)

c. Length of time that a lizard retreated after a simulated attack

d. A lizard's behavior rating from 0 (very shy) to 12 (very bold), based on how long it retreated under various attack conditions