Question

Italian sonnets consist of two parts, which part of sonnet is presented here from sonnet xIx

Answer 1

The answer is; the sestet!

Answer 2

Even though you didn't write the part of the sonnet, I believe I can still help you.
Every Italian sonnet has a fixed structure - it consists of 14 lines in total, which are divided into two parts. The first part is an octave - this means that the stanza consists of 8 lines. The second part is a sestet - this means that the stanza consists of 6 lines.
So depending on your part of the sonnet, it can either be an octave (if it has 8 lines), or a sestet (if it has 6 lines).