ATP biosynthesis takes place utilizing the $H^+$ gradient in mitochondria and chloroplasts. Identify the correct sites of $H^+$ gradient formation.
- Across the outer membrane of mitochondria and across the inner membrane of chloroplast
- Across the inner membrane of mitochondria and across the thylakoid membrane of chloroplast
- Within the matrix of mitochondria and across the inner membrane of chloroplast
- Within the matrix of mitochondria and Within the stroma of chloroplast