One who cannot easily pleased:

The correct answer is C. Fastidious.

A fastidious person is one who is very particular or demanding, especially about minor details. They may be difficult to please, and they may often be critical of others.

A cosmopolitan person is one who is familiar with or at home in many different countries or cultures. They may be well-traveled and have a broad range of interests.

A frightening person is one who is capable of causing fear or terror. They may be dangerous or threatening, and they may make others feel unsafe.

A feminist is a person