Question

osb stands for
oriented strong backer.
on site blocking.
organized strand boards.
oriented strand board.

Explanation:

OSB is a common construction material. Oriented strand board is the correct full - form. Oriented strong backer is not a recognized term for OSB. On - site blocking is an unrelated concept. Organized strand boards is an incorrect term; it should be oriented strand board (singular in the context of the material's name).

Answer:

oriented strand board.