Explanation:

- Option 1: Amla - Amla, or Indian gooseberry, is high in vitamin C and antioxidants. It doesn't contain significant oxalic acid.

- Option 2: Lemon - Lemons are known for their citric acid content. They do not have a high oxalic acid concentration.

- Option 3: Tamarind - Tamarind is rich in tartaric acid, not oxalic acid. It provides a tangy flavor in cooking.

- Option 4: Spinach - Spinach contains a high amount of oxalic acid. It's known for this trait, which can interfere with calcium absorption in the body.