The correct answer is C. I leave an attached image to have a clearer idea of the light process that uses the Light when entering the eye. When you have farsightedness, the image is formed behind the eye so the defective effect is generated.
What is sought with the lenses is to correct this condition and put the image back at the point of the retina.
The slope of the line on a velocityversus time graph is equal to the acceleration of the object. If the object is moving with an acceleration of +4 m/s/s (i.e., changing its velocity by 4 m/s per second), then the slope of the line will be +4 m/s/s.
Well let's analyse.
First we know Ohm's law of resistance that states:
Where R is resistance, U is voltage and I is current.
If we express current we get:
Because resistance cannot be equal to 0 (violation of mathematical law) the only thing that may cause current being zero is voltage.
Which means that as long as your voltage is bigger than 0V then there will be current (if we are talking about AC).
So to answer the question: Electric current is caused by voltage and regulated by resistance.
Hope this helps.
r3t40