What does a key signature indicate? a. what instruments to play the piece on b. what dynamic markings to use c. what scale the composition is based on d. what tempo to play the piece

Is this inappropriate language,”good evening,everyone. for coming out to sit on hard,uncomfortable stadium concrete on an unseasonably warm evening and wearing clothes and shoes you can’t wait to get home to get get ou of.” if so,how can i write it in formal?