Growing in numbers.

I recently read that Japan is considering plans to launch an advertising campaign to increasethe birth rate in its country, this strikes me as rather strange, after all Japan is already an overcrowded country, this made me wonder abotu possible ccauses for wanting an increased birth rate, remember these are guesses in the dark, im not too clued up about the facts on Japans population.

a) Due to the growing economy Japan believes it will need a greater workforce in the future.

b) Due to a prior baby boom tehy will require a new genereation to pay taxes to support the elderly.

c) After realising they have little farmland and are dependant on other countries for food they decide to try out a new source of nutrition.