In pride and prejudice both elizabeth an darcy have to struggle to what?

Naturally it is both. Austen examines both negative societal pressures and our internal biases that lead us to mistakes. Darcy and Elizabeth have to overcome all of these before they can allow themselves to fall in love and get married. 

Elizabeth's conflicts: 1. marrying for love or marrying for money/security to help her family (Mr. Collins is the threat, Charlotte actually takes this path) 2. Overcoming her own pride (or "vanity") in her perceptions so that she can see her mistakes in judging Wickham and Darcy 

Darcy's conflicts: 1. Societal pressure to marry with a girl from a rich, high-classed and well behaved family (not Elizabeth) 2. Learning to recognize his own arrogance 

Then there are other external conflicts- Lydia's elopement, Catherine de Bourgh's machinations, Caroline Bingley as a rival... 

A book never has one conflict, there will be many :)

Deep maybe or ambitious

Ithink the answer is c hope that works