A European put option with one month to maturity has a strike price of $30 on a stock that is presently priced at $28 and you assess may either rise to $35 or fall to $23 in that time. Let delta represent the number of puts needed to hedge one long share. Determine delta:

A) Cannot be determined as we do not have a risk-free rate

B) 12/7

C) -1.71428

D) -12/5

E) +2.4