Answer:
B. Watching TV
Step-by-step explanation:
Opportunity Cost is the cost of next best alternative forgone while choosing an alternative.
Eg: If I can consume apples & oranges, I like apples more than oranges. The opportunity cost of apples consumption is the next best option i.e oranges forgone.
As per given preferences : Book Reading > Watching TV > Listening Music
( '>' refers to preferred over)
The opportunity cost of Book reading is the next best option sacrifised i.e Watching TV.