ADJ.
innocent
VERB + UNSTUDIED
replied
UNSTUDIED + NOUN
modesty, topic
PREP.
in
adj
Free of artifice or cunning; innocent, spontaneous and unaffected.
an unstudied modesty
Not gained by study.
Not studied.
an unstudied topic
adjective — not by design or artifice
He replied in as unstudied and innocent a manner as possible so as not to arouse suspicion.