One Morning,Miles Accidentally Dropped a Thumbtack on the Chair of the Office

One morning,Miles accidentally dropped a thumbtack on the chair of the office manager where he worked.The office manager sat on the tack and two days later,was hospitalized with an infection caused by the tack.Which of the following is correct?

A) Miles actions were negligent.
B) No tort has been committed.
C) Miles committed an intentional tort.
D) Miles is strictly liable.