Topic: Right Form of Verb,

Best Answer Explained in Below-:

In the sentence "Everyone should the _________ truth," the missing word needs to fit grammatically in the context of the phrase. The phrase "should" is a modal verb that typically indicates obligation or recommendation, and it is followed by the base form of a verb.

Among the options provided:

- A) **speak**: This is the base form of the verb and is grammatically correct when paired with "should." The complete phrase would read: "Everyone should speak the truth," which expresses the idea that it is advisable or expected for everyone to communicate honestly.

- B) **speaking**: This is the present participle form of the verb, which would not correctly follow "should." It would not create a grammatically coherent phrase in this context.

- C) **spoken**: This is the past participle and does not fit after "should." It could be used in other contexts but not in this specific structure.

- D) **to speak**: This infinitive form disrupts the expected verb sequence after "should," as it should be in the base form without "to."

Therefore, the only option that fits correctly and maintains the grammatical structure of the sentence is **A) speak**.