Article XIII, Section 4 directs the State to undertake an agrarian reform program founded on the right of farmers and regular farmworkers who are landless:

The correct answer is A. To own directly or collectively the lands they till

Section 4 founds agrarian reform on the right of landless farmers and regular farmworkers to own directly or collectively the lands they till or, for other farmworkers, to receive a just share of the fruits.