Explanation:

The Central Building Research Institute (CBRI) is located in Roorkee, Uttarakhand, not Varanasi. This makes option B the mismatched pair. Options A (Birbal Sahni Institute of Palaeobotany - Lucknow), C (IIT Kanpur - Kanpur), and D (Acharya Narendra Dev University of Agriculture and Technology - Ayodhya) are all correctly matched institutions with their respective locations.