Which composition would have been used for an organ Mass?

What does it mean for Still's "A Black Pierrot" to be through-composed?

a. It has no verses. b. The music repeats with each verse. c. It follows a theme-and-variation type of formal structure. d. Each strophe receives its own musical setting.

The Classical composers expanded the Baroque concept of multi-movement compositions by

A. creating widely varied musical forms. B. developing and employing terraced dynamics in orchestral works. C. standardizing the number of movements for certain types of works. D. all of the above.