to increase the current in a circuit, which can be increased?\no voltage\no resistance\no interference\no ohms

Brief Explanations:

According to Ohm's law $I = \frac{V}{R}$, where $I$ is current, $V$ is voltage and $R$ is resistance. Current is directly proportional to voltage and inversely proportional to resistance. Increasing voltage will increase current, while increasing resistance will decrease it. Interference is not related to the basic relationship determining current magnitude in a simple - circuit context, and ohms is a unit of resistance.

Answer:

A. voltage