Which one is not connectivity cost reduction measure:

$$ a$.$

Mandated access to passive infrastructure;

b$.$

A centralized atlas of passive infrastructure;

c$.$

An obligation to equip all new buildings with high$-$speed internet $(100$ Mbps $)$ as well as mandated open access to the terminating segment.

d$.$

Government taking over financing of the networks

e$.$

A one$-$stop shop on rights of way and administrative procedures;

f$.$

A database where all planned civil works must be published;