Concept:The correct word cannot be chosen without the complete sentence that contains the blank.Explanation:The options are all intensifiers, but each is used in a specific pattern."too" often appears before an adjective followed by "to"."so" is used in the structure "so ... that"."very" and "quite" act as general intensifiers.Since the actual sentence is missing, no grammatical context is available.Answer:The correct option cannot be determined from the information provided.