Concept:The word “candid” means being open, honest, and straightforward in speech. Its synonym must share this meaning.Explanation:“Candid” describes someone who speaks honestly without hiding anything. The word “frank” also means open, sincere, and direct in expression. Both words convey the same idea of honesty. The other options are opposites: “dubious” means doubtful, “insincere” means dishonest, and “secretive” means hiding thoughts.Answer:The correct synonym is Frank (option A).