Please explain for the answer

[1] 12. A metallic electrode of the first kind exhibits a working curve slope of 11.83 mV per decade change in concentration. The measured solutions were at 25C. How many electrons are involved in this half- electrode reaction? a. n = 1 c. n = 3 e. n = 5 b. n = 2 = d. n=4 f. n = 6