correct formal command is Diga la verdad
The answer is the first option Diga
The right word to complete the given statemetn is Diga.
Diga la verdad
Mainly, because that's the right conjunction in this case, because the statement is refering to an order about saying the truth.
Therefore, the right answer is the first choice.
image 1 i think tengo
image 2 i think pido