A zero-level distribution channel means there are no intermediaries between the producer and the consumer. The product is sold directly through online platforms, company-owned stores, or direct orders. ‘Lens-o’ sells directly online and in its own retail showroom, hence it follows a zero-level channel. Other channels involve intermediaries like retailers (one level), wholesalers and retailers (two level), etc., which are not applicable here.
textbf{Final Answer:} (A) Zero level channel