Which of the following represents the biggest difference between asymmetric and symmetric cryptography?

asymmetric uses a short string of data for encryption, and symmetric uses a long string of data.
asymmetric uses random numbers for encryption, and symmetric uses mathematical algorithms.
asymmetric uses tokens for encryption, and symmetric uses a short string of data.
asymmetric uses two different keys for encryption, and symmetric uses one shared key.

The first two lines in this excerpt from "A Grain of Sand" by Frances Ellen Watkins indicate its subject, which is the very grain of sand. In the first line it is mentioned explicitly, whereas in the second one it is replaced with the third person singular pronoun it: "Do you know to me it (the grain of sand) brought just a simple loving thought?". It is a quite common resource for authors, since the use of pronouns prevent poems, as well as other kinds of literary and non-literary works, from being repetitive, that is, pronouns help authors avoid using the same word or term over and over again.