1.) a
2.) d
3.) b
because if look on the web the information will tell on what you need to now
B) herman von helmholtz
The trichromatic color theory<span> began in the 18th century, when </span>Thomas Young<span> proposed that color vision was a result of three different </span>photoreceptor cells<span>. </span>Hermann von Helmholtz<span> later expanded on Young's ideas using color-matching experiments which showed that people with normal vision needed three wavelengths to create the normal range of colors. Physiological evidence for trichromatic theory was later given by </span>Gunnar Svaetichin<span> (1956).</span>
Answer:
Line, texture, space, color, form, value and shape. (I believe that is the 3rd option listed)
Explanation:
Google! :)
