A European call and a European put on a stock have the same strike price and time to maturity. At 10:00am on a certain day, the price of the call is $3 and the price of the put is $4

At 10:01am news reaches the market that has no effect on the stock price or interest rates, but increases volatilities. As a result the price of the call changes to $4.50 . Which of the following is correct?
A. The put price increases to $6.00
B. The put price decreases to $2.00
C. The put price increases to $5.50
D. It is possible that there is no effect on the put price

C

The price of the call has increased by $1.50 . From put-call parity the price of the put must increase by the same amount. Hence the put price will become 4.00 +1.50 = $5.50 .