This invention was a commercial failure. Edison resolved that in the future he would only invent things that he was certain the public would want. ... This gave Edison the money he needed to set up his first small laboratory and manufacturing facility in Newark, New Jersey in 1871.
found at: https://www.nps.gov/edis/learn/historyculture/edison-biography.htm
b,d,f,e,c,a is the order in which it goes as the scientific method
Answer:
The inside is becoming positive.
Explanation:
The membrane potential may be defined as the difference in the electric potential between the outside and inside of the cell. This potential difference is important for the conduction of nerve impulse.
The depolarization of the cell occur due to the movement of sodium ions inside the cell. The depolarization of the cell changes the membrane potential from -70mV to +30mV. The inside of the cell become more positive than outside of the cell.
Thus, the correct answer is option (a).