Answer:
The constant of proportionality between charge and voltage is the capacitance.
Step-by-step explanation:
The capacitance (
), measured in farads, is the ratio of charge to voltage, that is:

Where:
- Charge, measured in coulombs.
- Voltage, measured in volts.
If charge is clear, it is easy to concluded that capacitante is a constant of direct proportionality.
Hence, the correct answer is B.