Which of the following statements with respect to the law of variable proportions is true?
1
The marginal product of a factor input initially falls with its employment level, but after reaching a certain level of employment, it starts falling even more, causing depression.
2
The marginal product of a factor input initially rises with its employment level and remains consistent throughout.
3
The marginal product of a factor input initially drops with its employment level, but after reaching a certain level of employment, it starts rising.
4
The marginal product of a factor input initially rises with its employment level, but after reaching a certain level of employment, it starts falling.