I agree Japan should change to more egalitarian society to raise the birth rate. And I guess all 3 options are actually not the options. Each single option isn't sufficient to solve the problem, so all 3 should be taken into actions.

Basically, essential problem of aging society will be the reduction of working population and the increase of social security expense. I find following kind of measures are necessary.

(1) Retirement age to be pulled up to the longest 75 years old. If from 65 years old to 74 years old employees work weekly 20 hour, social security expense can be reduced. (2) Abolish the work discrimination with sex and age. (3) Deploy work sharing system with identical work identical wages. (4) Enterprises and the schools to offer vocational education training for the citizens by low burden.