In a heat exchanger with steam outside the tubes, a liquid gets heated to 45 C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be

• A. less than 45 C
• B. more than 45 C
• C. equal to 45 C
• D. initially decreases and remains constant thereafter.