Gustav theodor fechner was a german philosopher and physicist who
a. founded psychophysics and developed techniques to measure sensation
b. developed a psychological law that would later be known as weber’s law
c. created several measurement techniques to measure light and sound
d. pioneered work on the powerful effects of subliminal stimulation

The correct answer is A. Gustav Theodor Fechner was a German philosopher and physicist who founded psychophysics and developed techniques to measure sensation.

Gustav Theodor Fechner was a philosopher and psychologist born in Gross Sarchen, Germany, known for formulating in 1860 an equation to quantify the relationship between a physical stimulus and the associated sensation, which would be known as Weber-Fechner law.

The correct answer is A. Founded psychophysics and developed techniques to measure sensation.

Explanation:

Gustav Theodor Fechner founded the experimental psychology which consists of the application of the scientific method in aspects related to behavior and mind. He also became the inspiration of many scientists and philosophers during the 20th-century.

Fechner contributed to the formation of what is today called experimental psychology but his major contribution was the fact of showing that mind could have a mathematical treatment and he also established that  psychology could be a quantified science.