How would you expect the vapor flow rate to vary with time?

Select answer from the options below

It should start at zero but approach $100\%$ of the molar feed flow rate over time.

It should abruptly change from zero to two thirds the molar feed flow rate at some time.

It should gradually increase from zero to two thirds of the molar feed flow rate and then remain constant.

It should decrease from zero to a negative value and then remain constant.

It should increase from zero and then oscillate about a mean value about $25\%$ of the molar feed flow rate.