Frankenstein Chapter 2, Excerpt 2 By Mary Shelley

Victor Frankenstein continues recounting the influences that lead to his great experiment:

Before this I was not unacquainted with the more obvious laws of electricity. On this occasion a man of great research in natural philosophy was with us, and excited by this catastrophe, he entered on the explanation of a theory which he had formed on the subject of electricity and galvanism, which was at once new and astonishing to me. All that he said threw greatly into the shade Cornelius Agrippa, Albertus Magnus, and Paracelsus, the lords of my imagination; but by some fatality the overthrow of these men disinclined me to pursue my accustomed studies. It seemed to me as if nothing would or could ever be known. All that had so long engaged my attention suddenly grew despicable. By one of those caprices of the mind which we are perhaps most subject to in early youth, I at once gave up my former occupations, set down natural history and all its progeny as a deformed and abortive creation, and entertained the greatest disdain for a would-be science which could never even step within the threshold of real knowledge. In this mood of mind I betook myself to the mathematics and the branches of study appertaining to that science as being built upon secure foundations, and so worthy of my consideration.

Which line from the text states that the narrator was young at the time?

By one of those caprices of the mind which we are perhaps most subject to in early youth. . .
I at once gave up my former occupations, set down natural history and all its progeny as a deformed and abortive creation. . .
In this mood of mind I betook myself to the mathematics. . .
. . .the branches of study appertaining to that science as being built upon secure foundations, and so worthy of my consideration.