Which type of market structure is characterized by a single seller with no close substitutes?

Which type of market structure is characterized by a single seller with no close substitutes?

کس قسم کے مارکیٹ ڈھانچے کی خصوصیت کسی ایک بیچنے والے کی طرف سے نہیں ہے جس میں کوئی قریبی متبادل نہیں ہے؟
Explanation

A Monopoly exists when there is only one seller in the market.

The product offered has no close substitutes, giving the seller full pricing power.