Final answer:
If a +5 nC charge results in five electric field lines, then a +20 nC charge, being four times greater, should result in twenty field lines.
Step-by-step explanation:
The question pertains to the concept of electric field lines which represent the magnitude and direction of the electric field around charged particles. In the given scenario, we're considering the proportional relationship between the quantity of charge and the number of electric field lines emanating from a charged object.
The rule for electric field lines is that the number of lines is proportional to the magnitude of the charge. So if a +5 nC charge emits five field lines, then a charge of +20 nC, which is four times greater, should emit four times the number of field lines, that is twenty field lines.