which among the following included as valid mean of knowledge?

Answer: Option A

In Classical Indian Philosophy, especially when discussing valid means of knowledge (pramanas), we're talking about how we can reliably gain true information about the world.

Inference (Anumana): This is a key pramana. It means arriving at new knowledge based on previously known truths or observations. Think of it like this: you see smoke and *infer* there is fire, even if you don't see the fire directly. This is a valid way to gain knowledge according to many schools of Indian philosophy.

Perception (Pratyaksha): While not explicitly mentioned in the options as the correct answer , but this is also a very important pramana - in Indian Epistemology means gaining knowledge through your senses like seeing, hearing, touching and etc.

Existence: Existence itself isn't a way *to know* something. It's what *is* known. It's the thing we're trying to understand through our means of knowledge.

Concept: A concept is an idea or thought. While important for understanding, concepts themselves aren't considered a direct *source* of valid knowledge in the same way that inference or perception is. Concepts are built upon knowledge gained through valid means.