Answer: Option B
Answer: (b)
Black market is the market in which illegal goods are traded. Goods acquired illegally take one of two price levels:
they may be cheaper than legal market prices as the supplier does not have to pay for production costs or taxes; or
they may be more expensive than legal market prices as the product is difficult to acquire or produce, dangerous to handle or not easily available legally.
Black-market transactions typically occur as a way for participants to avoid government price controls or taxes, conducting transactions 'under the table.'
So the most defining feature of black markets is that they have to be carried out secretly as they are illegal.