The passage indicates that one difference between the Italian sonnet and the English sonnet is that the

O total number of lines in each type of sonnet varies
O English sonnet is limited to two stanzas, whereas the Italian sonnet may have as many as eight
O Italian sonnet is composed of two stanzas, while the English sonnet is not
O Italian sonnet generally focuses on unrequited love, but the English sonnet usually celebrates requited love

The correct answer is: The total number of lines in each type of sonnet varies.