Humid defines as marked by a relatively high level of water vapor in the atmosphere. Basically, bringing moisture in the air, such as the air in a rain forest or the air of a dry desert.
The Petrarchan sonnet divides the 14 lines into two sections which are an eight-line stanza (octave) rhyming ABBAABBA, and a six-line stanza (sestet) rhyming CDCDCD or CDECDE.
I believe that the answer would be C.