The correct answer is "In other words": In other words, a database is a set of organized information (electronic) manipulated by a software.
"Possibly" and "Perhaps" are not correct because they express possibility,they are synonyms to "maybe" and "probably", so they don't have the same meaning as "or".
"Subsequently" and "Because of this" are synonyms to "as a result", "thus" and "consequently", they don't mean the same thing as "or".
