In $1967,$ Jacques Bertin published S$$miologie Graphique. In this book, he identified seven pre$-$attentive attributes $($two of which are related to the planar dimensions of x and y$)$ that our brains use to perceive data on a typical printed page without conscious effort, which are color, shape, size, value, position, texture, and $\_\_\_\_\_\_\_\_\_\_\_\_$

Select one:

a$.$

length

b$.$

orientation

c$.$

number

d$.$

density