The music reads that the theme in tenor from bar 71 is in dominant key,
while the theme in soprano from bar 76 is in tonic key, which are the
opposite theme-response relation from what you have already seen at the beginning of the piece.
Bass from bar 74 and tenor from bar 77 shown in blue are the motive゛C゛
already appeared in section 2, and you might also find brief descending and
ascending chromatic scales from bar 76.
The first theme in bass from bar 80 is tonally varied, which only happens
throughout Cp.8 and Cp.11.
The descending chromatic scale in soprano, which is the same
accompaniment to the inverted second theme, is parallel to this theme.
Coming together with the theme in alto is the fragment of the inverted
second theme at bar 85 and the motive ゛B"゛(in soprano at bar 86) in Cp.8.
Later, with another theme joined to the first theme and the second, a
tangle of voices see the three-theme combination.
