Answer
See the detailed answer below.
Work Step by Step
As we see in Figure 38.3, the graphs stay mostly horizontal when $ΔV\gt 0$ because all the electrons are being collected.
When the light intensity is stronger, it makes more electrons which leads to a higher current.
Classical physics scientists thought that the photoelectric effect was caused by heat (a thermal effect). If this were true, it means that stronger light would heat more electrons and hence more electrons are produced (emitted), giving them extra energy to move faster.
This means that the stronger light would create a larger "stopping voltage," which would show up on the graph as a shift to the left, as shown in the figure below.
Therefore, there will be no change on the right side of the graph, but the left side will change as shown below.
