1 Faraday can be defined as:
A. The magnitude of the charge of 1 mole of electrons.
B. The magnitude of the electric dipole.
C. A fundamental constant of nature equal to 6.63 $\times$ 10$^{-34}$ J s/photon.
D. A constant that accounts for the existence of ions in solution.
E. The assignment of charges to individual atoms.

Hint: The Faraday constant is symbolized by F, and is named after Michael Faraday. It is used in both physics, and chemistry, in the terms of electric charge. 1 Faraday can be calculated with the help of Avogadro constant.

Complete step by step answer:
1. Firstly, let us know about the Faraday constant. It is used in electrolysis calculations. The value of F was determined by weighing the amount of silver deposited in an electrochemical reaction.
2. We can say, this constant represents the magnitude of electric charge per mole of electrons.
3. Now, we know 1 mole of electrons = Avogadro’s number i.e. 6.022 $\times$ 10$^{23}$ per mole, and the Faraday constant is equal to the magnitude of charge of an electron i.e. 1.6 $\times$ 10$^{-19}$ C.
4. Thus, 1 Faraday is equal to the magnitude of charge of an electron multiplied by Avogadro’s number.
5. Therefore, 1 Faraday = 9.64870 $\times$ 10$^{4}$ coulombs/mole.
6. So, we can conclude that 1 Faraday is defined as the magnitude of the charge of 1 mole of electrons.
The correct option is A.

Note: The most common use of Faraday constant is in electrolysis, so you might think that it responds to the existence of ions in solution, but in the electrolysis the amount of charge in coulombs divided by the Faraday constant gives the amount in moles of elements that have been oxidised in the process.