Solve Applications Involving Expected Values

Solve applications involving expected values.
-A small business just leased a new computer and color laser printer for three years.
The service contract for the computer offers unlimited repairs for a fee of $100 a year
Plus a $25 service charge for each repair needed. The company's research indicates that
During a given year 86% of these computers need no repairs, 9% need to be repaired
Once, 4% twice, 1% three times, and none required more than three repairs. The standard
Deviation of the company's annual expense with the service contract for the computer is

A) $105.
B) $10.25.
C) $187.42.
D) $13.69.
E) $2.75.