which of these do brass instruments have? slides and reeds reeds and valves valves and slides

Brief Explanations:

Brass instruments produce sound through the vibration of the player's lips against a mouthpiece. They typically use valves (such as piston - valves or rotary - valves) or slides (like in the trombone) to change the pitch. Reeds are characteristic of woodwind instruments, not brass.

Answer:

C. Valves and slides