The characteristics of an electric field are analogous to a gravitational field, wave amplitudes influence each other only when aligned, electric-field lines from a positive charge spread radially, and it is not recommended to place credit cards with magnetic strips near magnets.
When comparing the characteristics of an electric field with a gravitational field, we find that the statement asserting their analogy is true. Electric fields, like gravitational fields, have field lines representing the force exerted on a test charge or mass. Moreover, the statement regarding the amplitude of waves is also true; the amplitude of one wave affects another when they coincide or are in phase with each other, leading to interference.
For the electric-field lines originating from a positive point charge, it's true that they spread out radially from the charge. Finally, placing magnetic strips near permanent magnets is indeed not recommended as it can demagnetize or otherwise damage the data encoded on the strip, which makes the correct answer true.