When can substitutions occur in a volleyball match?

Substitutions in a volleyball match can occur between rallies and during timeouts. This allows teams to make tactical changes, bring in fresh players, or adjust their lineup based on the current situation in the match. Making substitutions between rallies helps maintain the flow of the game while ensuring that teams can respond strategically to their opponents. During timeouts, this also provides players with an opportunity to rest and gives coaches a chance to communicate any game plan adjustments they may want to implement.

The option that states substitutions can only occur at the end of each set is incorrect, as this would severely limit the tactical opportunities and fluidity of the game. The option that allows substitutions only when a player is injured would not accommodate regular gameplay adjustments and could unnecessarily disrupt the match. Lastly, allowing substitutions at any point during a rally would be impractical and disruptive, as it would interfere with the pace and structure of the game. Therefore, the correct choice reflects the regulated moments in which substitutions can effectively and consistently occur.