Which of the following acids is found in spinach?

Oxalic acid

The correct answer is Option (4) - Oxalic acid

1. Formic Acid:
• Presence in Spinach: Formic acid is not found in spinach. It is more commonly associated with certain types of ants in nature.
2. Lactic Acid:
• Presence in Spinach: Lactic acid is not a prominent acid in spinach. It is more associated with fermented dairy products like curd.
3. Citric Acid:
• Presence in Spinach: Citric acid is not a major acid in spinach. It is commonly found in citrus fruits like lemons and oranges.
4. Oxalic Acid:
• Presence in Spinach: Oxalic acid is found in spinach.
• Explanation: Spinach contains oxalic acid, which is known to form crystals (oxalate crystals). However, it's important to note that oxalic acid can interfere with calcium absorption and could contribute to the formation of kidney stones in susceptible individuals.

In summary, among the options, oxalic acid is the acid found in spinach.