we / engage / individuals / appreciate nature / the relationship / they have with wildlife.

• A. 
  We should engage individuals to appreciate nature and the relationship that they have with wildlife.
• B. 
  We might engage individuals for appreciating nature and the relationship that they have with wildlife.
• C. 
  We must engage individuals to appreciate nature and the relationship when they have with wildlife.
• D. 
  We need engaging individuals to appreciate nature and the relationship which they have with wildlife.