The death rate decreased after the 1950s because 1. medical care
2. the climate
3. political situations
improved in several nations.
1. wars
2. infant mortality
3. food production
also began dropping dramatically.

1

Explanation:

All the other answers would raise the death rate, except for 3, but that wouldn't have such a profound impact to where the death rate would decrease by a substantial amount

answer; round wood logs, building materials like (plywood),also pulp and paper products;