The direction of an Electric Field is the direction

Question

a negative test charge will move in the field
a positive test charge will move in the field
either a positive or a negative test charge will move in the field***
the test charge may be either negative or positive

The direction of an electric field is defined as the direction of the force on a
negative test charge
positive test charge***
either a positive or negative test charge

Adding resistors in series changes the total resistance of a circuit by

increasing the resistance
decreasing the resistance
it does not affect the resistance
decrease the resistance if the value of the resistor added is less than the greatest resistor in the ciruit

I am unsure about the first two questions, and I am confused by the third question. Please help, thanks