After handing your client her medication, she says, "What is this blue tablet for? I have always taken a yellow pill.”. Your most appropriate action would be to:

Explain that the doctor probably changed her drug today to something more effective for her illness, and administer it.

Tell her briefly the action of the red tablet and administer it.

Withhold the drug until you have rechecked the MAR with her doctor's order sheet.

Administer the medication, but make a mental note to check on it later.