Option (A) Primary cell culture is correct because the textbook context clearly states that primary cell lines are prepared directly from the tissue of an organism. The context explains that for the preparation of primary cultures, a tissue is dissected in sterile conditions followed by mechanical or enzymatic disaggregation. The tissue can simply be chopped and pieces attached to a dish, and cells grow out from the fragment. The fragment of tissue is called an explant that may be transferred to a fresh dish. This direct inoculation from tissue to culture media characterizes primary cell culture. Secondary cell culture, on the other hand, involves sub-culturing or passaging cells after they have already been established from primary culture.