Read these sentences from the passage.
These words sank deep into my heart, stirred up sentiments within that lay slumbering, and called into existence an entirely new train of thought. It was a new and special revelation, explaining dark and mysterious things, with which my youthful understanding had struggled, but struggled in vain. I now understood what had been to me a most perplexing difficulty.
Which definition best expresses the connotative meaning of the word youthful as the author uses it in the second sentence?
A.brand new
B.ignorant
C.active
D.sensible