Use the Following Information for Questions

Multiple Choice

Use the following information for questions
Suppose there is one depositor who earns an income of $100 in each period.She spends $50 for consumption and the remainder goes to her savings account.Assume that a bank doesn't do anything with this money except safeguards it.The bank charges $5 for safeguarding fee.
-If the probability of theft is 0.2, what is the necessary and sufficient condition for personal safeguarding to be optimal?

A) The personal safeguarding fee is $5
B) The personal safeguarding fee is less than $5
C) The personal safeguarding fee is greater than $5
D) The personal safeguarding fee is between $5 and $10
E) Any fee would make personal safeguarding optimal