Claudia must have activated the "Truth Verifier" spell.
Although their relationship was quite good, the moment Princess Claudia asked the question, Ronald was certain she had initiated the "Truth Verifier" spell before entering his apartment.
Ronald himself could use the "Truth Verifier," and he naturally knew how long the spell lasted.
And this, essentially, was helping to dispel any doubts she might have about him.
So, upon hearing Claudia's question, he answered openly and confidently,
"Of course I have no problem with helping in research."
"But the spell we released at White Shore Castle requires several months of necessary buffering interval before it can be used again. It's clearly not feasible to apply it to the frequency of experimental activities at the research society."
"..."
Claudia's expression remained unchanged.
But after Ronald gave his answer, the princess fell silent for a few seconds before widening the distance between them.