Which of the following best explains the comparative anatomy of bird wings and fly wings? a). homologous structures
b). analogous structures
c). vestigial structured
d). embriological structures

I think its c out this mug

Some thought they were shadows of undiscovered planets crossing the Sun, while others believed they were dark clouds in the Sun's atmosphere. The movement of sunspots across the face of the Sun allowed astronomers in the early 1600's to make the first estimates of the Sun's rotation period (about 27 days).