The correct answer is: a) Guwahati
Guwahati is the capital of Assam and the largest city in the northeastern region of India. It is located on the banks of the Brahmaputra River and is a major commercial and cultural center. The city has a humid subtropical climate with hot, humid summers and mild, dry winters. The average temperature in Guwahati ranges from 22°C (72°F) in January to 30°C (86°F) in May.
Dibrugarh is the second largest city in Assam and is located in the upper Brahmaputra Valley. It is a major industrial and educational center. The city has a humid subtropical climate with hot, humid summers and mild, dry winters. The average temperature in Dibrugarh ranges from 21°C (70°F) in January to 31°C (88°F) in May.
Silchar is the third largest city in Assam and is located in the Barak Valley. It is a major commercial and educational center. The city has a humid subtropical climate with hot, humid summers and mild, dry winters. The average temperature in Silchar ranges from 20°C (68°F) in January to 32°C (90°F) in May.
Jorhat is the fourth largest city in Assam and is located in the Upper Assam Valley. It is a major commercial and educational center. The city has a humid subtropical climate with hot, humid summers and mild, dry winters. The average temperature in Jorhat ranges from 21°C (70°F) in January to 31°C (88°F) in May.
As you can see, all four cities in Assam have a humid subtropical climate with hot, humid summers and mild, dry winters. However, Guwahati has the highest average temperatures, followed by Dibrugarh, Silchar, and Jorhat.